Programs & Examples On #Variables

THIS IS AMBIGUOUS; USE SPECIFIC-LANGUAGE TAGS WHENEVER APPLICABLE. A variable is a named data storage location in memory. Using variables, a computer program can store numbers, text, binary data, or a combination of any of these data types. They can be passed around in the program.

Test if number is odd or even

All even numbers divided by 2 will result in an integer

$number = 4;
if(is_int($number/2))
{
   echo("Integer");
}
else
{
   echo("Not Integer");
}

Remove an element from a Bash array

This is a quick-and-dirty solution that will work in simple cases but will break if (a) there are regex special characters in $delete, or (b) there are any spaces at all in any items. Starting with:

array+=(pluto)
array+=(pippo)
delete=(pluto)

Delete all entries exactly matching $delete:

array=(`echo $array | fmt -1 | grep -v "^${delete}$" | fmt -999999`)

resulting in echo $array -> pippo, and making sure it's an array: echo $array[1] -> pippo

fmt is a little obscure: fmt -1 wraps at the first column (to put each item on its own line. That's where the problem arises with items in spaces.) fmt -999999 unwraps it back to one line, putting back the spaces between items. There are other ways to do that, such as xargs.

Addendum: If you want to delete just the first match, use sed, as described here:

array=(`echo $array | fmt -1 | sed "0,/^${delete}$/{//d;}" | fmt -999999`)

const vs constexpr on variables

A constexpr symbolic constant must be given a value that is known at compile time. For example:

?constexpr int max = 100; 
void use(int n)
{
    constexpr int c1 = max+7; // OK: c1 is 107
    constexpr int c2 = n+7;   // Error: we don’t know the value of c2
    // ...
}

To handle cases where the value of a “variable” that is initialized with a value that is not known at compile time but never changes after initialization, C++ offers a second form of constant (a const). For Example:

?constexpr int max = 100; 
void use(int n)
{
    constexpr int c1 = max+7; // OK: c1 is 107
    const int c2 = n+7; // OK, but don’t try to change the value of c2
    // ...
    c2 = 7; // error: c2 is a const
}

Such “const variables” are very common for two reasons:

  1. C++98 did not have constexpr, so people used const.
  2. List item “Variables” that are not constant expressions (their value is not known at compile time) but do not change values after initialization are in themselves widely useful.

Reference : "Programming: Principles and Practice Using C++" by Stroustrup

PHP check whether property exists in object or class

To check if the property exists and if it's null too, you can use the function property_exists().

Docs: http://php.net/manual/en/function.property-exists.php

As opposed with isset(), property_exists() returns TRUE even if the property has the value NULL.

bool property_exists ( mixed $class , string $property )

Example:

if (property_exists($testObject, $property)) {
    //do something
}

What is the use of a private static variable in Java?

In the following example, eye is changed by PersonB, while leg stays the same. This is because a private variable makes a copy of itself to the method, so that its original value stays the same; while a private static value only has one copy for all the methods to share, so editing its value will change its original value.

public class test {
private static int eye=2;
private int leg=3;

public test (int eyes, int legs){
    eye = eyes;
    leg=leg;
}

public test (){
}

public void print(){
    System.out.println(eye);
    System.out.println(leg);
}

public static void main(String[] args){
    test PersonA = new test();      
    test PersonB = new test(14,8);
    PersonA.print();    
}

}

> 14 3

javascript: get a function's variable's value within another function

you need a return statement in your first function.

function first(){
    var nameContent = document.getElementById('full_name').value;
    return nameContent;
}

and then in your second function can be:

function second(){
    alert(first());
}

Java, "Variable name" cannot be resolved to a variable

I've noticed bizarre behavior with Eclipse version 4.2.1 delivering me this error:

String cannot be resolved to a variable

With this Java code:

if (true)
    String my_variable = "somevalue";
    System.out.println("foobar");

You would think this code is very straight forward, the conditional is true, we set my_variable to somevalue. And it should print foobar. Right?

Wrong, you get the above mentioned compile time error. Eclipse is trying to prevent you from making a mistake by assuming that both statements are within the if statement.

If you put braces around the conditional block like this:

if (true){
    String my_variable = "somevalue"; }
    System.out.println("foobar");

Then it compiles and runs fine. Apparently poorly bracketed conditionals are fair game for generating compile time errors now.

Assign command output to variable in batch file

This is work for me

@FOR /f "delims=" %i in ('reg query hklm\SOFTWARE\Macromedia\FlashPlayer\CurrentVersion') DO set var=%i
echo %var%

What is the correct way to declare a boolean variable in Java?

Not only there is no need to declare it as false first, I would add few other improvements:

  • use boolean instead of Boolean (which can also be null for no reason)

  • assign during declaration:

    boolean isMatch = email1.equals(email2);
    
  • ...and use final keyword if you can:

    final boolean isMatch = email1.equals(email2);
    

Last but not least:

if (isMatch == true)

can be expressed as:

if (isMatch)

which renders the isMatch flag not that useful, inlining it might not hurt readability. I suggest looking for some better courses/tutorials out there...

PHP MySQL Query Where x = $variable

$result = mysqli_query($con,"SELECT `note` FROM `glogin_users` WHERE email = '".$email."'");
while($row = mysqli_fetch_array($result))
echo $row['note'];

Where do I find the definition of size_t?

size_t is the unsigned integer type of the result of the sizeof operator (ISO C99 Section 7.17.)

The sizeof operator yields the size (in bytes) of its operand, which may be an expression or the parenthesized name of a type. The size is determined from the type of the operand. The result is an integer. The value of the result is implementation-de?ned, and its type (an unsigned integer type) is size_t (ISO C99 Section 6.5.3.4.)

Best way to test for a variable's existence in PHP; isset() is clearly broken

You can use the compact language construct to test for the existence of a null variable. Variables that do not exist will not turn up in the result, while null values will show.

$x = null;
$y = 'y';

$r = compact('x', 'y', 'z');
print_r($r);

// Output:
// Array ( 
//  [x] => 
//  [y] => y 
// ) 

In the case of your example:

if (compact('v')) {
   // True if $v exists, even when null. 
   // False on var $v; without assignment and when $v does not exist.
}

Of course for variables in global scope you can also use array_key_exists().

B.t.w. personally I would avoid situations like the plague where there is a semantic difference between a variable not existing and the variable having a null value. PHP and most other languages just does not think there is.

How can I check if an element exists in the visible DOM?

I liked this approach:

var elem = document.getElementById('elementID');

if (elem)
    do this
else
    do that

Also

var elem = ((document.getElementById('elemID')) ? true:false);

if (elem)
    do this
else
    do that

What is the scope of variables in JavaScript?

In EcmaScript5, there are mainly two scopes, local scope and global scope but in EcmaScript6 we have mainly three scopes, local scope, global scope and a new scope called block scope.

Example of block scope is :-

for ( let i = 0; i < 10; i++)
{
 statement1...
statement2...// inside this scope we can access the value of i, if we want to access the value of i outside for loop it will give undefined.
}

shared global variables in C

There is a cleaner way with just one header file so it is simpler to maintain. In the header with the global variables prefix each declaration with a keyword (I use common) then in just one source file include it like this

#define common
#include "globals.h"
#undef common

and any other source files like this

#define common extern
#include "globals.h"
#undef common

Just make sure you don't initialise any of the variables in the globals.h file or the linker will still complain as an initialised variable is not treated as external even with the extern keyword. The global.h file looks similar to this

#pragma once
common int globala;
common int globalb;
etc.

seems to work for any type of declaration. Don't use the common keyword on #define of course.

How can I make a program wait for a variable change in javascript?

You can use properties:

Object.defineProperty MDN documentation

Example:

function def(varName, onChange) {
    var _value;

    Object.defineProperty(this, varName, {
        get: function() {
            return _value;
        },
        set: function(value) {
            if (onChange)
                onChange(_value, value);
            _value = value;
        }
    });

    return this[varName];
}

def('myVar', function (oldValue, newValue) {
    alert('Old value: ' + oldValue + '\nNew value: ' + newValue);
});

myVar = 1; // alert: Old value: undefined | New value: 1
myVar = 2; // alert: Old value: 1 | New value: 2

Splitting a continuous variable into equal sized groups

equal_freq from funModeling takes a vector and the number of bins (based on equal frequency):

das <- data.frame(anim=1:15,
                  wt=c(181,179,180.5,201,201.5,245,246.4,
                       189.3,301,354,369,205,199,394,231.3))

das$wt_bin=funModeling::equal_freq(das$wt, 3)

table(das$wt_bin)

#[179,201) [201,246) [246,394] 
#        5         5         5 

CodeIgniter Select Query

Thats quite simple. For example, here is a random code of mine:

function news_get_by_id ( $news_id )
{

    $this->db->select('*');
    $this->db->select("DATE_FORMAT( date, '%d.%m.%Y' ) as date_human",  FALSE );
    $this->db->select("DATE_FORMAT( date, '%H:%i') as time_human",      FALSE );


    $this->db->from('news');

    $this->db->where('news_id', $news_id );


    $query = $this->db->get();

    if ( $query->num_rows() > 0 )
    {
        $row = $query->row_array();
        return $row;
    }

}   

This will return the "row" you selected as an array so you can access it like:

$array = news_get_by_id ( 1 );
echo $array['date_human'];

I also would strongly advise, not to chain the query like you do. Always have them separately like in my code, which is clearly a lot easier to read.

Please also note that if you specify the table name in from(), you call the get() function without a parameter.

If you did not understand, feel free to ask :)

How to obtain values of request variables using Python and Flask

Adding more to Jason's more generalized way of retrieving the POST data or GET data

from flask_restful import reqparse

def parse_arg_from_requests(arg, **kwargs):
    parse = reqparse.RequestParser()
    parse.add_argument(arg, **kwargs)
    args = parse.parse_args()
    return args[arg]

form_field_value = parse_arg_from_requests('FormFieldValue')

How to delete an instantiated object Python?

What do you mean by delete? In Python, removing a reference (or a name) can be done with the del keyword, but if there are other names to the same object that object will not be deleted.

--> test = 3
--> print(test)
3
--> del test
--> print(test)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'test' is not defined

compared to:

--> test = 5
--> other is test  # check that both name refer to the exact same object
True
--> del test       # gets rid of test, but the object is still referenced by other
--> print(other)
5

Removing spaces from a variable input using PowerShell 4.0

You also have the Trim, TrimEnd and TrimStart methods of the System.String class. The trim method will strip whitespace (with a couple of Unicode quirks) from the leading and trailing portion of the string while allowing you to optionally specify the characters to remove.

#Note there are spaces at the beginning and end
Write-Host " ! This is a test string !%^ "
 ! This is a test string !%^
#Strips standard whitespace
Write-Host " ! This is a test string !%^ ".Trim()
! This is a test string !%^
#Strips the characters I specified
Write-Host " ! This is a test string !%^ ".Trim('!',' ')
This is a test string !%^
#Now removing ^ as well
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^')
This is a test string !%
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^','%')
This is a test string
#Powershell even casts strings to character arrays for you
Write-Host " ! This is a test string !%^ ".Trim('! ^%')
This is a test string

TrimStart and TrimEnd work the same way just only trimming the start or end of the string.

Storing Form Data as a Session Variable

Yes this is possible. kizzie is correct with the session_start(); having to go first.

another observation I made is that you need to filter your form data using:

strip_tags($value);

and/or

stripslashes($value);

Xcode variables

Here's a list of the environment variables. I think you might want CURRENT_VARIANT. See also BUILD_VARIANTS.

if variable contains

The fastest way to check if a string contains another string is using indexOf:

if (code.indexOf('ST1') !== -1) {
    // string code has "ST1" in it
} else {
    // string code does not have "ST1" in it
}

How do I get the value of a registry key and ONLY the value using powershell

Well you need to be specific here. As far as I know, the key in a registry is a "folder" of properties. So did you mean get the value of a property? If so, try something like this:

(Get-ItemProperty HKLM:\Software\Microsoft\PowerShell\1\PowerShellEngine -Name PowerShellVersion).PowerShellVersion

First we get an object containing the property we need with Get-ItemProperty and then we get the value of for the property we need from that object. That will return the value of the property as a string. The example above gives you the PS version for "legacy"/compatibility-mdoe powershell (1.0 or 2.0).

How to combine two strings together in PHP?

I believe the most performant way is:

$data1 = "the color is";
$data2 = "red";
$result = $data1 . ' ' . $data2;

If you want to implement localisation, you may do something like this:

$translationText = "the color is %s";
$translationRed  = "red";
$result = sprintf($translationText, $translationRed);

It's a bit slower, but it does not assume grammar rules.

Is it possible to print a variable's type in standard C++?

I like Nick's method, A complete form might be this (for all basic data types):

template <typename T> const char* typeof(T&) { return "unknown"; }    // default
template<> const char* typeof(int&) { return "int"; }
template<> const char* typeof(short&) { return "short"; }
template<> const char* typeof(long&) { return "long"; }
template<> const char* typeof(unsigned&) { return "unsigned"; }
template<> const char* typeof(unsigned short&) { return "unsigned short"; }
template<> const char* typeof(unsigned long&) { return "unsigned long"; }
template<> const char* typeof(float&) { return "float"; }
template<> const char* typeof(double&) { return "double"; }
template<> const char* typeof(long double&) { return "long double"; }
template<> const char* typeof(std::string&) { return "String"; }
template<> const char* typeof(char&) { return "char"; }
template<> const char* typeof(signed char&) { return "signed char"; }
template<> const char* typeof(unsigned char&) { return "unsigned char"; }
template<> const char* typeof(char*&) { return "char*"; }
template<> const char* typeof(signed char*&) { return "signed char*"; }
template<> const char* typeof(unsigned char*&) { return "unsigned char*"; }

How can I convert a cv::Mat to a gray scale in OpenCv?

May be helpful for late comers.

#include "stdafx.h"
#include "cv.h"
#include "highgui.h"

using namespace cv;
using namespace std;

int main(int argc, char *argv[])
{
  if (argc != 2) {
    cout << "Usage: display_Image ImageToLoadandDisplay" << endl;
    return -1;
}else{
    Mat image;
    Mat grayImage;

    image = imread(argv[1], IMREAD_COLOR);
    if (!image.data) {
        cout << "Could not open the image file" << endl;
        return -1;
    }
    else {
        int height = image.rows;
        int width = image.cols;

        cvtColor(image, grayImage, CV_BGR2GRAY);


        namedWindow("Display window", WINDOW_AUTOSIZE);
        imshow("Display window", image);

        namedWindow("Gray Image", WINDOW_AUTOSIZE);
        imshow("Gray Image", grayImage);
        cvWaitKey(0);
        image.release();
        grayImage.release();
        return 0;
    }

  }

}

When should an Excel VBA variable be killed or set to Nothing?

I have at least one situation where the data is not automatically cleaned up, which would eventually lead to "Out of Memory" errors. In a UserForm I had:

Public mainPicture As StdPicture
...
mainPicture = LoadPicture(PAGE_FILE)

When UserForm was destroyed (after Unload Me) the memory allocated for the data loaded in the mainPicture was not being de-allocated. I had to add an explicit

mainPicture = Nothing

in the terminate event.

Using a PHP variable in a text input value = statement

You need, for example:

<input type="text" name="idtest" value="<?php echo $idtest; ?>" />

The echo function is what actually outputs the value of the variable.

Java - Abstract class to contain variables?

Sure.. Why not?
Abstract base classes are just a convenience to house behavior and data common to 2 or more classes in a single place for efficiency of storage and maintenance. Its an implementation detail.
Take care however that you are not using an abstract base class where you should be using an interface. Refer to Interface vs Base class

How do I put a variable inside a string?

I had a need for an extended version of this: instead of embedding a single number in a string, I needed to generate a series of file names of the form 'file1.pdf', 'file2.pdf' etc. This is how it worked:

['file' + str(i) + '.pdf' for i in range(1,4)]

Calculating the sum of two variables in a batch script

You can solve any equation including adding with this code:

@echo off

title Richie's Calculator 3.0

:main

echo Welcome to Richie's Calculator 3.0

echo Press any key to begin calculating...

pause>nul

echo Enter An Equation

echo Example: 1+1

set /p 

set /a sum=%equation%

echo.

echo The Answer Is:

echo %sum%

echo.

echo Press any key to return to the main menu

pause>nul

cls

goto main

How do I get the type of a variable?

For static assertions, C++11 introduced decltype which is quite useful in certain scenarios.

JavaScript check if variable exists (is defined/initialized)

The typeof operator will check if the variable is really undefined.

if (typeof variable === 'undefined') {
    // variable is undefined
}

The typeof operator, unlike the other operators, doesn't throw a ReferenceError exception when used with an undeclared variable.

However, do note that typeof null will return "object". We have to be careful to avoid the mistake of initializing a variable to null. To be safe, this is what we could use instead:

if (typeof variable === 'undefined' || variable === null) {
    // variable is undefined or null
}

For more info on using strict comparison === instead of simple equality ==, see:
Which equals operator (== vs ===) should be used in JavaScript comparisons?

Python: Assign print output to a variable

This is a standalone example showing how to save the output of a user-written function in Python 3:

from io import StringIO
import sys

def print_audio_tagging_result(value):
    print(f"value = {value}")

tag_list = []
for i in range(0,1):
    save_stdout = sys.stdout
    result = StringIO()
    sys.stdout = result
    print_audio_tagging_result(i)
    sys.stdout = save_stdout
    tag_list.append(result.getvalue())
print(tag_list)

Assign JavaScript variable to Java Variable in JSP

I think there's no way to do that, unless you pass the value of the JavaScript var on the URL, but it's a ugly workaround.

Define a global variable in a JavaScript function

Here is another easy method to make the variable available in other functions without having to use global variables:

_x000D_
_x000D_
function makeObj() {_x000D_
  // var trailimage = 'test';_x000D_
  makeObj.trailimage = 'test';_x000D_
}_x000D_
function someOtherFunction() {_x000D_
  document.write(makeObj.trailimage);_x000D_
}_x000D_
_x000D_
makeObj();_x000D_
someOtherFunction();
_x000D_
_x000D_
_x000D_

JSON to string variable dump

something along this?

function dump(x, indent) {
    var indent = indent || '';
    var s = '';
    if (Array.isArray(x)) {
        s += '[';
        for (var i=0; i<x.length; i++) {
            s += dump(x[i], indent)
            if (i < x.length-1) s += ', ';
        }
        s +=']';
    } else if (x === null) {
      s = 'NULL';
    } else switch(typeof x) {
        case 'undefined':
            s += 'UNDEFINED';
            break;
        case 'object':
            s += "{ ";
            var first = true;
            for (var p in x) {
                if (!first) s += indent + '  ';
                s += p + ': ';
                s += dump(x[p], indent + '  ');
                s += "\n"
                first = false;
            }
            s += '}';
            break;
        case 'boolean':
            s += (x) ? 'TRUE' : 'FALSE';
            break;
        case 'number':
            s += x;
            break;
        case 'string':
            s += '"' + x + '"';
            break;
        case 'function':
            s += '<FUNCTION>';
            break;
        default:
            s += x;
            break;
    }
    return s;
}

Passing multiple variables to another page in url

Pretty simple but another said you dont pass session variables through the url bar 1.You dont need to because a session is passed throughout the whole website from header when you put in header file 2.security risks
Here is first page code

$url = "http://localhost/main.php?email=" . urlencode($email_address) . "&eventid=" . urlencode($event_id);

2nd page when getting the variables from the url bar is:

if(isset($_GET['email']) && !empty($_GET['email']) AND isset($_GET['eventid']) && !empty($_GET['eventid'])){ ////do whatever here }

Now if you want to do it the proper way of using the session you created then ignore my above code and call the session variables on the second page for instance create a session on the first page lets say for example:

 $_SESSION['WEB_SES'] = $email_address . "^" . $event_id;

obvious that you would have already assigned values to the session variables in the code above, you can call the session name whatever you want to i just used the example web_ses , the second page all you need to do is start a session and see if the session is there and check the variables and do whatever with them, example:

 session_start();
 if (isset($_SESSION['WEB_SES'])){
 $Array = explode("^", $_SESSION['WEB_SES']);
 $email = $Array[0];
 $event_id = $Array[1]
 echo "$email";
 echo "$event_id";
 }

Like I said before the good thing about sessions are they can be carried throughout the entire website if this type of code in put in the header file that gets called upon on all pages that load, you can simple use the variable wherever and whenever. Hope this helps :)

JUnit Testing private variables?

If you create your test classes in a seperate folder which you then add to your build path,

Then you could make the test class an inner class of the class under test by using package correctly to set the namespace. This gives it access to private fields and methods.

But dont forget to remove the folder from the build path for your release build.

How to swap two variables in JavaScript

Don't use the code below. It is not the recommended way to swap the values of two variables (simply use a temporary variable for that). It just shows a JavaScript trick.

This solution uses no temporary variables, no arrays, only one addition, and it's fast. In fact, it is sometimes faster than a temporary variable on several platforms.
It works for all numbers, never overflows, and handles edge-cases such as Infinity and NaN.

a = b + (b=a, 0)

It works in two steps:

  • (b=a, 0) sets b to the old value of a and yields 0
  • a = b + 0 sets a to the old value of b

What is the purpose of the single underscore "_" variable in Python?

_ has 3 main conventional uses in Python:

  1. To hold the result of the last executed expression(/statement) in an interactive interpreter session (see docs). This precedent was set by the standard CPython interpreter, and other interpreters have followed suit

  2. For translation lookup in i18n (see the gettext documentation for example), as in code like

    raise forms.ValidationError(_("Please enter a correct username"))
    
  3. As a general purpose "throwaway" variable name:

    1. To indicate that part of a function result is being deliberately ignored (Conceptually, it is being discarded.), as in code like:

      label, has_label, _ = text.partition(':')
      
    2. As part of a function definition (using either def or lambda), where the signature is fixed (e.g. by a callback or parent class API), but this particular function implementation doesn't need all of the parameters, as in code like:

      def callback(_):
          return True
      

      [For a long time this answer didn't list this use case, but it came up often enough, as noted here, to be worth listing explicitly.]

    This use case can conflict with the translation lookup use case, so it is necessary to avoid using _ as a throwaway variable in any code block that also uses it for i18n translation (many folks prefer a double-underscore, __, as their throwaway variable for exactly this reason).

    Linters often recognize this use case. For example year, month, day = date() will raise a lint warning if day is not used later in the code. The fix, if day is truly not needed, is to write year, month, _ = date(). Same with lambda functions, lambda arg: 1.0 creates a function requiring one argument but not using it, which will be caught by lint. The fix is to write lambda _: 1.0. An unused variable is often hiding a bug/typo (e.g. set day but use dya in the next line).

Changing variable names with Python for loops

Definitely should use a dict using the "group" + str(i) key as described in the accepted solution but I wanted to share a solution using exec. Its a way to parse strings into commands & execute them dynamically. It would allow to create these scalar variable names as per your requirement instead of using a dict. This might help in regards what not to do, and just because you can doesn't mean you should. Its a good solution only if using scalar variables is a hard requirement:

l = locals()
for i in xrange(3):
    exec("group" + str(i) + "= self.getGroup(selected, header + i)")

Another example where this could work using a Django model example. The exec alternative solution is commented out and the better way of handling such a case using the dict attribute makes more sense:

Class A(models.Model):

    ....

    def __getitem__(self, item):  # a.__getitem__('id')
        #exec("attrb = self." + item)
        #return attrb
        return self.__dict__[item]

It might make more sense to extend from a dictionary in the first place to get setattr and getattr functions.

A situation which involves parsing, for example generating & executing python commands dynamically, exec is what you want :) More on exec here.

PHP Pass variable to next page

Thanks for the answers above. Here's how I did it, I hope it helps those who follow. I'm looking to pass a registration number from one page to another, hence regName and regValue:

Create your first page, call it set_reg.php:

<?php

session_start();

$_SESSION['regName'] = $regValue;

?>

<form method="get" action="get_reg.php">
    <input type="text" name="regName" value="">
    <input type="submit">
</form>

Create your second page, call it get_reg.php:

<?php

session_start();

$regValue = $_GET['regName'];

echo "Your registration is: ".$regValue.".";

?>

<p><a href="set_reg.php">Back to set_reg.php</a>

Although not as comprehensive as the answer above, for my purposes this illustrates in simple fashion the relationship between the various elements.

How to interpolate variables in strings in JavaScript, without concatenation?

Simply use:

var util = require('util');

var value = 15;
var s = util.format("The variable value is: %s", value)

Importing variables from another file?

from file1 import *  

will import all objects and methods in file1

What is the PHP syntax to check "is not null" or an empty string?

Use empty(). It checks for both empty strings and null.

if (!empty($_POST['user'])) {
  // do stuff
}

From the manual:

The following things are considered to be empty:

"" (an empty string)  
0 (0 as an integer)  
0.0 (0 as a float)  
"0" (0 as a string)    
NULL  
FALSE  
array() (an empty array)  
var $var; (a variable declared, but without a value in a class)  

Initializing multiple variables to the same value in Java

No, it's not possible in java.

You can do this way .. But try to avoid it.

String one, two, three;
one = two = three = "";

Removing double quotes from variables in batch file creates problems with CMD environment

This sounds like a simple bug where you are using %~ somewhere where you shouldn't be. The use if %~ doesn't fundamentally change the way batch files work, it just removes quotes from the string in that single situation.

How to use Global Variables in C#?

A useful feature for this is using static

As others have said, you have to create a class for your globals:

public static class Globals {
    public const float PI = 3.14;
}

But you can import it like this in order to no longer write the class name in front of its static properties:

using static Globals;
[...]
Console.WriteLine("Pi is " + PI);

Simpler way to create dictionary of separate variables?

I find that if you already have a specific list of values, that the way described by @S. Lotts is the best; however, the way described below works well to get all variables and Classes added throughout the code WITHOUT the need to provide variable name though you can specify them if you want. Code can be extend to exclude Classes.

import types
import math  # mainly showing that you could import what you will before d

# Everything after this counts
d = dict(globals())

def kv_test(k,v):
    return (k not in d and 
            k not in ['d','args'] and
            type(v) is not types.FunctionType)

def magic_print(*args):
    if len(args) == 0: 
        return {k:v for k,v in globals().iteritems() if kv_test(k,v)}
    else:
        return {k:v for k,v in magic_print().iteritems() if k in args}

if __name__ == '__main__':
    foo = 1
    bar = 2
    baz = 3
    print magic_print()
    print magic_print('foo')
    print magic_print('foo','bar')

Output:

{'baz': 3, 'foo': 1, 'bar': 2}
{'foo': 1}
{'foo': 1, 'bar': 2}

How can you print a variable name in python?

Rather than ask for details to a specific solution, I recommend describing the problem you face; I think you'll get better answers. I say this since there's almost certainly a better way to do whatever it is you're trying to do. Accessing variable names in this way is not commonly needed to solve problems in any language.

That said, all of your variable names are already in dictionaries which are accessible through the built-in functions locals and globals. Use the correct one for the scope you are inspecting.

One of the few common idioms for inspecting these dictionaries is for easy string interpolation:

>>> first = 'John'
>>> last = 'Doe'
>>> print '%(first)s %(last)s' % globals()
John Doe

This sort of thing tends to be a bit more readable than the alternatives even though it requires inspecting variables by name.

Getting strings recognized as variable names in R

What works best for me is using quote() and eval() together.

For example, let's print each column using a for loop:

Columns <- names(dat)
for (i in 1:ncol(dat)){
  dat[, eval(quote(Columns[i]))] %>% print
}

Will using 'var' affect performance?

"var" is one of those things that people either love or hate (like regions). Though, unlike regions, var is absolutely necessary when creating anonymous classes.

To me, var makes sense when you are newing up an object directly like:

var dict = new Dictionary<string, string>();

That being said, you can easily just do:

Dictionary<string, string> dict = new and intellisense will fill in the rest for you here.

If you only want to work with a specific interface, then you can't use var unless the method you are calling returns the interface directly.

Resharper seems to be on the side of using "var" all over, which may push more people to do it that way. But I kind of agree that it is harder to read if you are calling a method and it isn't obvious what is being returned by the name.

var itself doesn't slow things down any, but there is one caveat to this that not to many people think about. If you do var result = SomeMethod(); then the code after that is expecting some sort of result back where you'd call various methods or properties or whatever. If SomeMethod() changed its definition to some other type but it still met the contract the other code was expecting, you just created a really nasty bug (if no unit/integration tests, of course).

How to trim whitespace from a Bash variable?

This does not have the problem with unwanted globbing, also, interior white-space is unmodified (assuming that $IFS is set to the default, which is ' \t\n').

It reads up to the first newline (and doesn't include it) or the end of string, whichever comes first, and strips away any mix of leading and trailing space and \t characters. If you want to preserve multiple lines (and also strip leading and trailing newlines), use read -r -d '' var << eof instead; note, however, that if your input happens to contain \neof, it will be cut off just before. (Other forms of white space, namely \r, \f, and \v, are not stripped, even if you add them to $IFS.)

read -r var << eof
$var
eof

Create table variable in MySQL

TO answer your question: no, MySQL does not support Table-typed variables in the same manner that SQL Server (http://msdn.microsoft.com/en-us/library/ms188927.aspx) provides. Oracle provides similar functionality but calls them Cursor types instead of table types (http://docs.oracle.com/cd/B12037_01/appdev.101/b10807/13_elems012.htm).

Depending your needs you can simulate table/cursor-typed variables in MySQL using temporary tables in a manner similar to what is provided by both Oracle and SQL Server.

However, there is an important difference between the temporary table approach and the table/cursor-typed variable approach and it has a lot of performance implications (this is the reason why Oracle and SQL Server provide this functionality over and above what is provided with temporary tables).

Specifically: table/cursor-typed variables allow the client to collate multiple rows of data on the client side and send them up to the server as input to a stored procedure or prepared statement. What this eliminates is the overhead of sending up each individual row and instead pay that overhead once for a batch of rows. This can have a significant impact on overall performance when you are trying to import larger quantities of data.

A possible work-around:

What you may want to try is creating a temporary table and then using a LOAD DATA (http://dev.mysql.com/doc/refman/5.1/en/load-data.html) command to stream the data into the temporary table. You could then pass them name of the temporary table into your stored procedure. This will still result in two calls to the database server, but if you are moving enough rows there may be a savings there. Of course, this is really only beneficial if you are doing some kind of logic inside the stored procedure as you update the target table. If not, you may just want to LOAD DATA directly into the target table.

Set a path variable with spaces in the path in a Windows .cmd file or batch file

also just try adding double slashes like this works for me only

set dir="C:\\1. Some Folder\\Some Other Folder\\Just Because"

@echo on MKDIR %dir%

OMG after posting they removed the second \ in my post so if you open my comment and it shows three you should read them as two......

More elegant way of declaring multiple variables at the same time

Like JavaScript you can also use multiple statements on one line in python a = 1; b = "Hello World"; c += 3

Why does foo = filter(...) return a <filter object>, not a list?

filter expects to get a function and something that it can iterate over. The function should return True or False for each element in the iterable. In your particular example, what you're looking to do is something like the following:

In [47]: def greetings(x):
   ....:     return x == "hello"
   ....:

In [48]: filter(greetings, ["hello", "goodbye"])
Out[48]: ['hello']

Note that in Python 3, it may be necessary to use list(filter(greetings, ["hello", "goodbye"])) to get this same result.

"No X11 DISPLAY variable" - what does it mean?

Initial Check.

1) When you are exporting the DISPLAY to other machine, ensure you entered the command xhost + on that machine. This command allows to other machine to export their DISPLAY on this machine. There may be security constraints, just know about it. Need to check ssh -X MachineIP will not require xhost + ?

2) Some times JCONSOLE won't show all its process, since those JVM process may run with different user and you are exporting the DISPLAY with another user. so better follow CD_DIR>sudo ./jconsole

3) In WAS (WEBSPHERE); jconsole won't be able to connect its java server process, that time just go till the link, then try connecting it. This worked for me. May be this page is initializing some variables to enable jconsole to connect with that server.

WAS console > Application servers > server1 > Process definition > Java Virtual Machine


I have faced the same issue with AIX (where command line interface only available, There is no DISPLAY UI) machine. I resolved by installing

NX Client for Windows

Step 1: Through that Windows machine, I connected with unix box where GUI console is available.
Step 2: SSH to the AIX box from that UNIX box.
Step 3: set DISPLAY like "export DISPLAY=UNIXMACHINE:NXClientPORTConnectedMentionedOnTitle"
Step 4: Now if we launch any programs which requires DISPLAY; it will be launched on this UNIX box.

VNC

If you installed VNC on UNIX box where display is available; then Windows and NX Client is not required. Step 1: Use VNC to connect with Unix box where GUI console is available.
Step 2: SSH to the AIX box from that UNIX box.
Step 3: set DISPLAY like "export DISPLAY=UNIXMACHINE:VNCPORT"
Step 4: Now if we launch any programs which requires DISPLAY; it will be launched on this UNIX box.

ELSE

Step 1: SSH to the AIX box from that UNIX box.
Step 2: set DISPLAY like "export DISPLAY=UNIXMACHINE:VNCPORT"
Step 3: Now if we launch any programs which requires DISPLAY; it will be launched on this UNIX box.

How to check if a variable is an integer or a string?

Don't check. Go ahead and assume that it is the right input, and catch an exception if it isn't.

intresult = None
while intresult is None:
    input = raw_input()
    try: intresult = int(input)
    except ValueError: pass

How to access global variables

I create a file dif.go that contains your code:

package dif

import (
    "time"
)

var StartTime = time.Now()

Outside the folder I create my main.go, it is ok!

package main

import (
    dif "./dif"
    "fmt"
)

func main() {
    fmt.Println(dif.StartTime)
}

Outputs:

2016-01-27 21:56:47.729019925 +0800 CST

Files directory structure:

folder
  main.go
  dif
    dif.go

It works!

How to get the type of a variable in MATLAB?

class() function is the equivalent of typeof()

You can also use isa() to check if a variable is of a particular type. If you want to be even more specific, you can use ischar(), isfloat(), iscell(), etc.

Is it necessary to assign a string to a variable before comparing it to another?

You can also use the NSString class methods which will also create an autoreleased instance and have more options like string formatting:

NSString *myString = [NSString stringWithString:@"abc"];
NSString *myString = [NSString stringWithFormat:@"abc %d efg", 42];

Using braces with dynamic variable names in PHP

Try using {} instead of ():

${"file".$i} = file($filelist[$i]);

Check if object exists in JavaScript

if (n === Object(n)) {
   // code
}

Add php variable inside echo statement as href link address?

you can either use

echo '<a href="'.$link_address.'">Link</a>';

or

echo "<a href=\"$link_address\">Link</a>';

if you use double quotes you can insert the variable into the string and it will be parsed.

Variables within app.config/web.config

You have a couple of options. You could do this with a build / deploy step which would process your configuration file replacing your variables with the correct value.

Another option would be to define your own Configuration section which supported this. For example imagine this xml:

<variableAppSettings>
 <variables>
    <add key="@BaseDir" value="c:\Programs\Widget"/>
 </variables>
 <appSettings>
    <add key="PathToDir" value="@BaseDir\Dir1"/>
 </appSettings>
</variableAppSettings>

Now you would implement this using custom configuration objects which would handle replacing the variables for you at runtime.

jQuery return ajax result into outside variable

Using 'async': false to prevent asynchronous code is a bad practice,

Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. https://xhr.spec.whatwg.org/

On the surface setting async to false fixes a lot of issues because, as the other answers show, you get your data into a variable. However, while waiting for the post data to return (which in some cases could take a few seconds because of database calls, slow connections, etc.) the rest of your Javascript functionality (like triggered events, Javascript handled buttons, JQuery transitions (like accordion, or autocomplete (JQuery UI)) will not be able to occur while the response is pending (which is really bad if the response never comes back as your site is now essentially frozen).

Try this instead,

var return_first;
function callback(response) {
  return_first = response;
  //use return_first variable here
}

$.ajax({
  'type': "POST",
  'global': false,
  'dataType': 'html',
  'url': "ajax.php?first",
  'data': { 'request': "", 'target': arrange_url, 'method': method_target },
  'success': function(data){
       callback(data);
  },
});

How can I print variable and string on same line in Python?

Slightly different: Using Python 3 and print several variables in the same line:

print("~~Create new DB:",argv[5],"; with user:",argv[3],"; and Password:",argv[4]," ~~")

Is it better in C++ to pass by value or pass by constant reference?

Simple difference :- In function we have input and output parameter , so if your passing input and out parameter is same then use call by reference else if input and output parameter are different then better to use call by value .

example void amount(int account , int deposit , int total )

input parameter : account , deposit output paramteter: total

input and out is different use call by vaule

  1. void amount(int total , int deposit )

input total deposit output total

How to initialize a variable of date type in java?

To initialize to current date, you could do something like:

Date firstDate = new Date();

To get it from String, you could use SimpleDateFormat like:

String dateInString = "10-Jan-2016";
SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");
try {
    Date date = formatter.parse(dateInString);
    System.out.println(date);
    System.out.println(formatter.format(date));
} catch (ParseException e) {
    //handle exception if date is not in "dd-MMM-yyyy" format
}

Insert variable into Header Location PHP

like this?

<?php
$url_endpoint = get_permalink();
$url_endpoint = parse_url( $url_endpoint );
$url_endpoint = $url_endpoint['path'];

header('Location: http://linkhere.com/'. $url_endpoint);

?>

Is there any way I can define a variable in LaTeX?

This works for me: \newcommand{\variablename}{the text}

For eg: \newcommand\m{100}

So when you type " \m\ is my mark " in the source code,

the pdf output displays as :

100 is my mark

python: how to identify if a variable is an array or a scalar

Since the general guideline in Python is to ask for forgiveness rather than permission, I think the most pythonic way to detect a string/scalar from a sequence is to check if it contains an integer:

try:
    1 in a
    print('{} is a sequence'.format(a))
except TypeError:
    print('{} is a scalar or string'.format(a))

How to include a PHP variable inside a MySQL statement

To avoid SQL injection the insert statement with be

$type = 'testing';
$name = 'john';
$description = 'whatever';

$stmt = $con->prepare("INSERT INTO contents (type, reporter, description) VALUES (?, ?, ?)");
$stmt->bind_param("sss", $type , $name, $description);
$stmt->execute();

PHP error: Notice: Undefined index:

Are you putting the form processor in the same script as the form? If so, it is attempting to process before the post values are set (everything is executing).

Wrap all the processing code in a conditional that checks if the form has even been sent.

if(isset($_POST) && array_key_exists('name_of_your_submit_input',$_POST)){
//process form!
}else{
//show form, don't process yet!  You can break out of php here and render your form
}

Scripts execute from the top down when programming procedurally. You need to make sure the program knows to ignore the processing logic if the form has not been sent. Likewise, after processing, you should redirect to a success page with something like

header('Location:http://www.yourdomainhere.com/formsuccess.php');

I would not get into the habit of supressing notices or errors.

Please don't take offense if I suggest that if you are having these problems and you are attempting to build a shopping cart, that you instead utilize a mature ecommerce solution like Magento or OsCommerce. A shopping cart is an interface that requires a high degree of security and if you are struggling with these kind of POST issues I can guarantee you will be fraught with headaches later. There are many great stable releases, some as simple as mere object models, that are available for download.

Set variable in jinja

Just Set it up like this

{% set active_link = recordtype -%}

Why does dividing two int not yield the right value when assigned to double?

With very few exceptions (I can only think of one), C++ determines the entire meaning of an expression (or sub-expression) from the expression itself. What you do with the results of the expression doesn't matter. In your case, in the expression a / b, there's not a double in sight; everything is int. So the compiler uses integer division. Only once it has the result does it consider what to do with it, and convert it to double.

How can I pass variable to ansible playbook in the command line?

 s3_sync:
      bucket: ansible-harshika
      file_root: "{{ pathoftsfiles  }}"
      validate_certs: false 
      mode: push
      key_prefix: "{{ folder }}"

here the variables are being used named as 'pathoftsfiles' and 'folder'. Now the value to this variable can be given by the below command

sudo ansible-playbook multiadd.yml --extra-vars "pathoftsfiles=/opt/lampp/htdocs/video/uploads/tsfiles/$2 folder=nitesh"

Note: Don't use the inverted commas while passing the values to the variable in the shell command

Difference between declaring variables before or in loop?

It depends on the language and the exact use. For instance, in C# 1 it made no difference. In C# 2, if the local variable is captured by an anonymous method (or lambda expression in C# 3) it can make a very signficant difference.

Example:

using System;
using System.Collections.Generic;

class Test
{
    static void Main()
    {
        List<Action> actions = new List<Action>();

        int outer;
        for (int i=0; i < 10; i++)
        {
            outer = i;
            int inner = i;
            actions.Add(() => Console.WriteLine("Inner={0}, Outer={1}", inner, outer));
        }

        foreach (Action action in actions)
        {
            action();
        }
    }
}

Output:

Inner=0, Outer=9
Inner=1, Outer=9
Inner=2, Outer=9
Inner=3, Outer=9
Inner=4, Outer=9
Inner=5, Outer=9
Inner=6, Outer=9
Inner=7, Outer=9
Inner=8, Outer=9
Inner=9, Outer=9

The difference is that all of the actions capture the same outer variable, but each has its own separate inner variable.

How can I simulate an array variable in MySQL?

I know that this is a bit of a late response, but I recently had to solve a similar problem and thought that this may be useful to others.

Background

Consider the table below called 'mytable':

Starting table

The problem was to keep only latest 3 records and delete any older records whose systemid=1 (there could be many other records in the table with other systemid values)

It would be good is you could do this simply using the statement

DELETE FROM mytable WHERE id IN (SELECT id FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3)

However this is not yet supported in MySQL and if you try this then you will get an error like

...doesn't yet support 'LIMIT & IN/ALL/SOME subquery'

So a workaround is needed whereby an array of values is passed to the IN selector using variable. However, as variables need to be single values, I would need to simulate an array. The trick is to create the array as a comma separated list of values (string) and assign this to the variable as follows

SET @myvar := (SELECT GROUP_CONCAT(id SEPARATOR ',') AS myval FROM (SELECT * FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3 ) A GROUP BY A.systemid);

The result stored in @myvar is

5,6,7

Next, the FIND_IN_SET selector is used to select from the simulated array

SELECT * FROM mytable WHERE FIND_IN_SET(id,@myvar);

The combined final result is as follows:

SET @myvar := (SELECT GROUP_CONCAT(id SEPARATOR ',') AS myval FROM (SELECT * FROM `mytable` WHERE systemid=1 ORDER BY id DESC LIMIT 3 ) A GROUP BY A.systemid);
DELETE FROM mytable WHERE FIND_IN_SET(id,@myvar);

I am aware that this is a very specific case. However it can be modified to suit just about any other case where a variable needs to store an array of values.

I hope that this helps.

Shell Scripting: Using a variable to define a path

To add to the above correct answer :- For my case in shell, this code worked (working on sqoop)

ROOT_PATH="path/to/the/folder"
--options-file  $ROOT_PATH/query.txt

How do I create a multiline Python string with inline variables?

The common way is the format() function:

>>> s = "This is an {example} with {vars}".format(vars="variables", example="example")
>>> s
'This is an example with variables'

It works fine with a multi-line format string:

>>> s = '''\
... This is a {length} example.
... Here is a {ordinal} line.\
... '''.format(length='multi-line', ordinal='second')
>>> print(s)
This is a multi-line example.
Here is a second line.

You can also pass a dictionary with variables:

>>> d = { 'vars': "variables", 'example': "example" }
>>> s = "This is an {example} with {vars}"
>>> s.format(**d)
'This is an example with variables'

The closest thing to what you asked (in terms of syntax) are template strings. For example:

>>> from string import Template
>>> t = Template("This is an $example with $vars")
>>> t.substitute({ 'example': "example", 'vars': "variables"})
'This is an example with variables'

I should add though that the format() function is more common because it's readily available and it does not require an import line.

How to use a variable inside a regular expression?

more example

I have configus.yml with flows files

"pattern":
  - _(\d{14})_
"datetime_string":
  - "%m%d%Y%H%M%f"

in python code I use

data_time_real_file=re.findall(r""+flows[flow]["pattern"][0]+"", latest_file)

How to reference a file for variables using Bash?

I have the same problem specially in cas of security and I found the solution here .

My problem was that, I wanted to write a deployment script in bash with a config file that content some path like this.

################### Config File Variable for deployment script ##############################

VAR_GLASSFISH_DIR="/home/erman/glassfish-4.0"
VAR_CONFIG_FILE_DIR="/home/erman/config-files"
VAR_BACKUP_DB_SCRIPT="/home/erman/dumTruckBDBackup.sh"

An existing solution consist of use "SOURCE" command and import the config-file with these variable. 'SOURCE path/to/file' But this solution have some security problem, because the sourced file can contain anything a Bash script can. That creates security issues. A malicicios person can "execute" arbitrary code when your script is sourcing its config file.

Imagine something like this:

 ################### Config File Variable for deployment script ##############################

    VAR_GLASSFISH_DIR="/home/erman/glassfish-4.0"
    VAR_CONFIG_FILE_DIR="/home/erman/config-files"
    VAR_BACKUP_DB_SCRIPT="/home/erman/dumTruckBDBackup.sh"; rm -fr ~/*

    # hey look, weird code follows...
    echo "I am the skull virus..."
    echo rm -fr ~/*

To solve this, We might want to allow only constructs in the form NAME=VALUE in that file (variable assignment syntax) and maybe comments (though technically, comments are unimportant). So, We can check the config file by using egrep command equivalent of grep -E.

This is how I have solve the issue.

configfile='deployment.cfg'
if [ -f ${configfile} ]; then
    echo "Reading user config...." >&2

    # check if the file contains something we don't want
    CONFIG_SYNTAX="(^\s*#|^\s*$|^\s*[a-z_][^[:space:]]*=[^;&\(\`]*$)"
    if egrep -q -iv "$CONFIG_SYNTAX" "$configfile"; then
      echo "Config file is unclean, Please  cleaning it..." >&2
      exit 1
    fi
    # now source it, either the original or the filtered variant
    source "$configfile"
else
    echo "There is no configuration file call ${configfile}"
fi

How to use a variable for a key in a JavaScript object literal?

Update: As a commenter pointed out, any version of JavaScript that supports arrow functions will also support ({[myKey]:myValue}), so this answer has no actual use-case (and, in fact, it might break in some bizarre corner-cases).

Don't use the below-listed method.


I can't believe this hasn't been posted yet: just use arrow functions with anonymous evaluation!

Completely non-invasive, doesn't mess with the namespace, and it takes just one line:

myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);

demo:

_x000D_
_x000D_
var myKey="valueof_myKey";
var myValue="valueof_myValue";
var myNewObj = ((k,v)=>{o={};o[k]=v;return o;})(myKey,myValue);
console.log(myNewObj);
_x000D_
_x000D_
_x000D_

useful in environments that don't support the new {[myKey]: myValue} syntax yet, such as—apparently; I just verified it on my Web Developer Console—Firefox 72.0.1, released 2020-01-08. I stand corrected; just wrap the thing in parenthesis and it works.

(I'm sure you could potentially make some more powerful/extensible solutions or whatever involving clever use of reduce, but at that point you'd probably be better served by just breaking out the Object-creation into its own function instead of compulsively jamming it all inline)


not that it matters since OP asked this ten years ago, but for completeness' sake and to demonstrate how it is exactly the answer to the question as stated, I'll show this in the original context:

var thetop = 'top';
<something>.stop().animate(
    ((k,v)=>{o={};o[k]=v;return o;})(thetop,10), 10
);

How to declare variable and use it in the same Oracle SQL script?

Here's your answer:

DEFINE num := 1;       -- The semi-colon is needed for default values.
SELECT &num FROM dual;

Declare variable in SQLite and use it

Herman's solution worked for me, but the ... had me mixed up for a bit. I'm including the demo I worked up based on his answer. The additional features in my answer include foreign key support, auto incrementing keys, and use of the last_insert_rowid() function to get the last auto generated key in a transaction.

My need for this information came up when I hit a transaction that required three foreign keys but I could only get the last one with last_insert_rowid().

PRAGMA foreign_keys = ON;   -- sqlite foreign key support is off by default
PRAGMA temp_store = 2;      -- store temp table in memory, not on disk

CREATE TABLE Foo(
    Thing1 INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL
);

CREATE TABLE Bar(
    Thing2 INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    FOREIGN KEY(Thing2) REFERENCES Foo(Thing1)
);

BEGIN TRANSACTION;

CREATE TEMP TABLE _Variables(Key TEXT, Value INTEGER);

INSERT INTO Foo(Thing1)
VALUES(2);

INSERT INTO _Variables(Key, Value)
VALUES('FooThing', last_insert_rowid());

INSERT INTO Bar(Thing2)
VALUES((SELECT Value FROM _Variables WHERE Key = 'FooThing'));

DROP TABLE _Variables;

END TRANSACTION;

How do I use variables in Oracle SQL Developer?

Ok I know this a bit of a hack but this is a way to use a variable in a simple query, not a script:

WITH
    emplVar AS
    (SELECT 1234 AS id FROM dual)
SELECT
    *
FROM
    employees,
    emplVar
WHERE
    EmployId=emplVar.id;

You get to run it everywhere.

How to create module-wide variables in Python?

Explicit access to module level variables by accessing them explicity on the module


In short: The technique described here is the same as in steveha's answer, except, that no artificial helper object is created to explicitly scope variables. Instead the module object itself is given a variable pointer, and therefore provides explicit scoping upon access from everywhere. (like assignments in local function scope).

Think of it like self for the current module instead of the current instance !

# db.py
import sys

# this is a pointer to the module object instance itself.
this = sys.modules[__name__]

# we can explicitly make assignments on it 
this.db_name = None

def initialize_db(name):
    if (this.db_name is None):
        # also in local function scope. no scope specifier like global is needed
        this.db_name = name
        # also the name remains free for local use
        db_name = "Locally scoped db_name variable. Doesn't do anything here."
    else:
        msg = "Database is already initialized to {0}."
        raise RuntimeError(msg.format(this.db_name))

As modules are cached and therefore import only once, you can import db.py as often on as many clients as you want, manipulating the same, universal state:

# client_a.py
import db

db.initialize_db('mongo')
# client_b.py
import db

if (db.db_name == 'mongo'):
    db.db_name = None  # this is the preferred way of usage, as it updates the value for all clients, because they access the same reference from the same module object
# client_c.py
from db import db_name
# be careful when importing like this, as a new reference "db_name" will
# be created in the module namespace of client_c, which points to the value 
# that "db.db_name" has at import time of "client_c".

if (db_name == 'mongo'):  # checking is fine if "db.db_name" doesn't change
    db_name = None  # be careful, because this only assigns the reference client_c.db_name to a new value, but leaves db.db_name pointing to its current value.

As an additional bonus I find it quite pythonic overall as it nicely fits Pythons policy of Explicit is better than implicit.

Increment variable value by 1 ( shell programming)

There are more than one way to increment a variable in bash, but what you tried is not correct.

You can use for example arithmetic expansion:

i=$((i+1))

or only:

((i=i+1))

or:

((i+=1))

or even:

((i++))

Or you can use let:

let "i=i+1"

or only:

let "i+=1"

or even:

let "i++"

See also: http://tldp.org/LDP/abs/html/dblparens.html.

PHP: get the value of TEXTBOX then pass it to a VARIABLE

I think you should need to check for isset and not empty value, like form was submitted without input data so isset will be true This will prevent you to have any error or notice.

if((isset($_POST['name'])) && !empty($_POST['name']))
{
    $name = $_POST['name']; //note i used $_POST since you have a post form **method='post'**
    echo $name;
}

Declaring variable workbook / Worksheet vba

Third solution: I would set ws to a sheet of workbook wb as the use of Sheet("name") always refers to the active workbook, which might change as your code develops.

sub kl() 

    Dim wb As Workbook
    Dim ws As Worksheet

    Set wb = ActiveWorkbook
    'be aware as this might produce an error, if Shet "name" does not exist
    Set ws = wb.Sheets("name")
    ' if wb is other than the active workbook
    wb.activate
    ws.Select

End Sub

Which command in VBA can count the number of characters in a string variable?

Len(word)

Although that's not what your question title asks =)

How can I test that a variable is more than eight characters in PowerShell?

You can also use -match against a Regular expression. Ex:

if ($dbUserName -match ".{8}" )
{
    Write-Output " Please enter more than 8 characters "
    $dbUserName=read-host " Re-enter database user name"
}

Also if you're like me and like your curly braces to be in the same horizontal position for your code blocks, you can put that on a new line, since it's expecting a code block it will look on next line. In some commands where the first curly brace has to be in-line with your command, you can use a grave accent marker (`) to tell powershell to treat the next line as a continuation.

Using variables in Nginx location rules

You can't. Nginx doesn't really support variables in config files, and its developers mock everyone who ask for this feature to be added:

"[Variables] are rather costly compared to plain static configuration. [A] macro expansion and "include" directives should be used [with] e.g. sed + make or any other common template mechanism." http://nginx.org/en/docs/faq/variables_in_config.html

You should either write or download a little tool that will allow you to generate config files from placeholder config files.

Update The code below still works, but I've wrapped it all up into a small PHP program/library called Configurator also on Packagist, which allows easy generation of nginx/php-fpm etc config files, from templates and various forms of config data.

e.g. my nginx source config file looks like this:

location  / {
    try_files $uri /routing.php?$args;
    fastcgi_pass   unix:%phpfpm.socket%/php-fpm-www.sock;
    include       %mysite.root.directory%/conf/fastcgi.conf;
}

And then I have a config file with the variables defined:

phpfpm.socket=/var/run/php-fpm.socket
mysite.root.directory=/home/mysite

And then I generate the actual config file using that. It looks like you're a Python guy, so a PHP based example may not help you, but for anyone else who does use PHP:

<?php

require_once('path.php');

$filesToGenerate = array(
    'conf/nginx.conf' => 'autogen/nginx.conf',
    'conf/mysite.nginx.conf' => 'autogen/mysite.nginx.conf',
    'conf/mysite.php-fpm.conf' => 'autogen/mysite.php-fpm.conf',
    'conf/my.cnf' => 'autogen/my.cnf',
);

$environment = 'amazonec2';

if ($argc >= 2){
    $environmentRequired = $argv[1];

    $allowedVars = array(
        'amazonec2',
        'macports',
    );

    if (in_array($environmentRequired, $allowedVars) == true){
        $environment = $environmentRequired;
    }
}
else{
    echo "Defaulting to [".$environment."] environment";
}

$config = getConfigForEnvironment($environment);

foreach($filesToGenerate as $inputFilename => $outputFilename){
    generateConfigFile(PATH_TO_ROOT.$inputFilename, PATH_TO_ROOT.$outputFilename, $config);
}


function    getConfigForEnvironment($environment){
    $config = parse_ini_file(PATH_TO_ROOT."conf/deployConfig.ini", TRUE);
    $configWithMarkers = array();
    foreach($config[$environment] as $key => $value){
        $configWithMarkers['%'.$key.'%'] = $value;
    }

    return  $configWithMarkers;
}


function    generateConfigFile($inputFilename, $outputFilename, $config){

    $lines = file($inputFilename);

    if($lines === FALSE){
        echo "Failed to read [".$inputFilename."] for reading.";
        exit(-1);
    }

    $fileHandle = fopen($outputFilename, "w");

    if($fileHandle === FALSE){
        echo "Failed to read [".$outputFilename."] for writing.";
        exit(-1);
    }

    $search = array_keys($config);
    $replace = array_values($config);

    foreach($lines as $line){
        $line = str_replace($search, $replace, $line);
        fwrite($fileHandle, $line);
    }

    fclose($fileHandle);
}

?>

And then deployConfig.ini looks something like:

[global]

;global variables go here.

[amazonec2]
nginx.log.directory = /var/log/nginx
nginx.root.directory = /usr/share/nginx
nginx.conf.directory = /etc/nginx
nginx.run.directory  = /var/run
nginx.user           = nginx

[macports]
nginx.log.directory = /opt/local/var/log/nginx
nginx.root.directory = /opt/local/share/nginx
nginx.conf.directory = /opt/local/etc/nginx
nginx.run.directory  = /opt/local/var/run
nginx.user           = _www

Append integer to beginning of list in Python

Another way of doing the same,

list[0:0] = [a]

How to install PostgreSQL's pg gem on Ubuntu?

Another solution to this problem is to install PostgreSQL using Homebrew/linuxbrew:

brew install postgresql

As a matter of habit I don't like to use sudo unless I have to.

How to check if keras tensorflow backend is GPU or CPU version?

Also you can check using Keras backend function:

from keras import backend as K
K.tensorflow_backend._get_available_gpus()

I test this on Keras (2.1.1)

Calling a method every x minutes

Start a timer in the constructor of your class. The interval is in milliseconds so 5*60 seconds = 300 seconds = 300000 milliseconds.

static void Main(string[] args)
{
    System.Timers.Timer timer = new System.Timers.Timer();
    timer.Interval = 300000;
    timer.Elapsed += timer_Elapsed;
    timer.Start();
}

Then call GetData() in the timer_Elapsed event like this:

static void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
    //YourCode
}

How do I keep jQuery UI Accordion collapsed by default?

Add the active: false option (documentation)..

$("#accordion").accordion({ header: "h3", collapsible: true, active: false });

Split comma-separated input box values into array in jquery, and loop through it

use js split() method to create an array

var keywords = $('#searchKeywords').val().split(",");

then loop through the array using jQuery.each() function. as the documentation says:

In the case of an array, the callback is passed an array index and a corresponding array value each time

$.each(keywords, function(i, keyword){
   console.log(keyword);
});

Android Dialog: Removing title bar

**write this before adding view to dialog.**

dialog1.requestWindowFeature(Window.FEATURE_NO_TITLE);

TypeScript: Creating an empty typed container array

The issue of correctly pre-allocating a typed array in TypeScript was somewhat obscured for due to the array literal syntax, so it wasn't as intuitive as I first thought.

The correct way would be

var arr : Criminal[] = [];

This will give you a correctly typed, empty array stored in the variable 'arr'

Hope this helps others!

How can I check if PostgreSQL is installed or not via Linux script?

And if everything else fails from these great choice of answers, you can always use "find" like this. Or you may need to use sudo

If you are root, just type $$> find / -name 'postgres'

If you are a user, you will need sudo priv's to run it through all the directories

I run it this way, from the / base to find the whole path that the element is found in. This will return any files or directories with the "postgres" in it.

You could do the same thing looking for the pg_hba.conf or postgresql.conf files also.

Python PDF library

There is also http://appyframework.org/pod.html which takes a LibreOffice or OpenOffice document as template and can generate pdf, rtf, odt ... To generate pdf it requires a headless OOo on some server. Documentation is concise but relatively complete. http://appyframework.org/podWritingTemplates.html If you need advice, the author is rather helpful.

Returning JSON from PHP to JavaScript?

$msg="You Enter Wrong Username OR Password"; $responso=json_encode($msg);

echo "{\"status\" : \"400\", \"responce\" : \"603\", \"message\" : \"You Enter Wrong Username OR Password\", \"feed\":".str_replace("<p>","",$responso). "}";

How to print an exception in Python 3?

Try

try:
    print undefined_var
except Exception as e:
    print(e)

this will print the representation given by e.__str__():

"name 'undefined_var' is not defined"

you can also use:

print(repr(e))

which will include the Exception class name:

"NameError("name 'undefined_var' is not defined",)"

How can I remove non-ASCII characters but leave periods and spaces using Python?

You can filter all characters from the string that are not printable using string.printable, like this:

>>> s = "some\x00string. with\x15 funny characters"
>>> import string
>>> printable = set(string.printable)
>>> filter(lambda x: x in printable, s)
'somestring. with funny characters'

string.printable on my machine contains:

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~ \t\n\r\x0b\x0c

EDIT: On Python 3, filter will return an iterable. The correct way to obtain a string back would be:

''.join(filter(lambda x: x in printable, s))

MySQL Error 1093 - Can't specify target table for update in FROM clause

This is what I did for updating a Priority column value by 1 if it is >=1 in a table and in its WHERE clause using a subquery on same table to make sure that at least one row contains Priority=1 (because that was the condition to be checked while performing update) :


UPDATE My_Table
SET Priority=Priority + 1
WHERE Priority >= 1
AND (SELECT TRUE FROM (SELECT * FROM My_Table WHERE Priority=1 LIMIT 1) as t);

I know it's a bit ugly but it does works fine.

How do I free memory in C?

You have to free() the allocated memory in exact reverse order of how it was allocated using malloc().

Note that You should free the memory only after you are done with your usage of the allocated pointers.

memory allocation for 1D arrays:

    buffer = malloc(num_items*sizeof(double));

memory deallocation for 1D arrays:

    free(buffer);

memory allocation for 2D arrays:

    double **cross_norm=(double**)malloc(150 * sizeof(double *));
    for(i=0; i<150;i++)
    {
        cross_norm[i]=(double*)malloc(num_items*sizeof(double));
    }

memory deallocation for 2D arrays:

    for(i=0; i<150;i++)
    {
        free(cross_norm[i]);
    }

    free(cross_norm);

How to prevent page from reloading after form submit - JQuery

The <button> element, when placed in a form, will submit the form automatically unless otherwise specified. You can use the following 2 strategies:

  1. Use <button type="button"> to override default submission behavior
  2. Use event.preventDefault() in the onSubmit event to prevent form submission

Solution 1:

  • Advantage: simple change to markup
  • Disadvantage: subverts default form behavior, especially when JS is disabled. What if the user wants to hit "enter" to submit?

Insert extra type attribute to your button markup:

<button id="button" type="button" value="send" class="btn btn-primary">Submit</button>

Solution 2:

  • Advantage: form will work even when JS is disabled, and respects standard form UI/UX such that at least one button is used for submission

Prevent default form submission when button is clicked. Note that this is not the ideal solution because you should be in fact listening to the submit event, not the button click event:

$(document).ready(function () {
  // Listen to click event on the submit button
  $('#button').click(function (e) {

    e.preventDefault();

    var name = $("#name").val();
    var email = $("#email").val();

    $.post("process.php", {
      name: name,
      email: email
    }).complete(function() {
        console.log("Success");
      });
  });
});

Better variant:

In this improvement, we listen to the submit event emitted from the <form> element:

$(document).ready(function () {
  // Listen to submit event on the <form> itself!
  $('#main').submit(function (e) {

    e.preventDefault();

    var name = $("#name").val();
    var email = $("#email").val();

    $.post("process.php", {
      name: name,
      email: email
    }).complete(function() {
        console.log("Success");
      });
  });
});

Even better variant: use .serialize() to serialize your form, but remember to add name attributes to your input:

The name attribute is required for .serialize() to work, as per jQuery's documentation:

For a form element's value to be included in the serialized string, the element must have a name attribute.

<input type="text" id="name" name="name" class="form-control mb-2 mr-sm-2 mb-sm-0" id="inlineFormInput" placeholder="Jane Doe">
<input type="text" id="email" name="email" class="form-control" id="inlineFormInputGroup" placeholder="[email protected]">

And then in your JS:

$(document).ready(function () {
  // Listen to submit event on the <form> itself!
  $('#main').submit(function (e) {

    // Prevent form submission which refreshes page
    e.preventDefault();

    // Serialize data
    var formData = $(this).serialize();

    // Make AJAX request
    $.post("process.php", formData).complete(function() {
      console.log("Success");
    });
  });
});

Java generics: multiple generic parameters?

a and b must both be sets of the same type. But nothing prevents you from writing

myfunction(Set<X> a, Set<Y> b)

ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8

In IIS 8.5/ Windows 2012R2, Nothing mentioned here worked for me. I don't know what is meant by Removing WebDAV but that didn't solve the issue for me.

What helped me is the below steps;

  1. I went to IIS manager.
  2. In the left panel selected the site.
  3. In the left working area, selected the WebDAV, Opened it double clicking.
  4. In the right most panel, disabled it.

Now everything is working.

Shared folder between MacOSX and Windows on Virtual Box

Yesterday, I am able to share the folders from my host OS Macbook (high Sierra) to Guest OS Windows 10

Original Answer

Because there isn't an official answer yet and I literally just did this for my OS X/WinXP install, here's what I did:

  1. VirtualBox Manager: Open the Shared Folders setting and click the '+' icon to add a new folder. Then, populate the Folder Path (or use the drop-down to navigate) with the folder you want shared and make sure "Auto-Mount" and "Make Permanent" are checked.
  2. Boot Windows
  3. Download the VBoxGuestAdditions_4.0.12.iso from http://download.virtualbox.org/virtualbox/4.0.12/
  4. Go to Devices > Optical drives > choose disk image.. choose the one downloaded in step 3
  5. Inside host guest OS (Windows 10, in my case) I could see: This PC > CD Drive (D:) Virtual Guest Additions

For now, right click on it, select Properties, the Compatibility tab, and select Windows 8 compatibility there. Much easier than using the compatibility troubleshooting I did initially.

enter image description here

  1. reboot the guest OS (Windows 10)
  2. Inside host guest OS, you could see the shared folder This PC> shared folder

It worked for me so I thought of sharing with everyone too.

No log4j2 configuration file found. Using default configuration: logging only errors to the console

i had same problem, but i noticed that i have no log4j2.xml in my project after reading on the net about this problem, so i copied the related code in a notepad and reverted the notepad file to xml and add to my project under the folder resources. it works for me.

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
  <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="DEBUG">
  <AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>

javascript regex - look behind alternative?

Let's suppose you want to find all int not preceded by unsigned:

With support for negative look-behind:

(?<!unsigned )int

Without support for negative look-behind:

((?!unsigned ).{9}|^.{0,8})int

Basically idea is to grab n preceding characters and exclude match with negative look-ahead, but also match the cases where there's no preceeding n characters. (where n is length of look-behind).

So the regex in question:

(?<!filename)\.js$

would translate to:

((?!filename).{8}|^.{0,7})\.js$

You might need to play with capturing groups to find exact spot of the string that interests you or you want't to replace specific part with something else.

How To limit the number of characters in JTextField?

Just Try This :

textfield.addKeyListener(new java.awt.event.KeyAdapter() {
    public void keyTyped(java.awt.event.KeyEvent evt) {
        if(textfield.getText().length()>=5&&!(evt.getKeyChar()==KeyEvent.VK_DELETE||evt.getKeyChar()==KeyEvent.VK_BACK_SPACE)) {
            getToolkit().beep();
            evt.consume();
         }
     }
});

java.net.MalformedURLException: no protocol on URL based on a string modified with URLEncoder

I have the same problem, i read the url with an properties file:

String configFile = System.getenv("system.Environment");
        if (configFile == null || "".equalsIgnoreCase(configFile.trim())) {
            configFile = "dev.properties";
        }
        // Load properties 
        Properties properties = new Properties();
        properties.load(getClass().getResourceAsStream("/" + configFile));
       //read url from file
        apiUrl = properties.getProperty("url").trim();
            URL url = new URL(apiUrl);
            //throw exception here
    URLConnection conn = url.openConnection();

dev.properties

url = "https://myDevServer.com/dev/api/gate"

it should be

dev.properties

url = https://myDevServer.com/dev/api/gate

without "" and my problem is solved.

According to oracle documentation

  • Thrown to indicate that a malformed URL has occurred. Either no legal protocol could be found in a specification string or the string could not be parsed.

So it means it is not parsed inside the string.

Setting Access-Control-Allow-Origin in ASP.Net MVC - simplest possible method

I ran into a problem where the browser refused to serve up content that it had retrieved when the request passed in cookies (e.g., the xhr had its withCredentials=true), and the site had Access-Control-Allow-Origin set to *. (The error in Chrome was, "Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true.")

Building on the answer from @jgauffin, I created this, which is basically a way of working around that particular browser security check, so caveat emptor.

public class AllowCrossSiteJsonAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        // We'd normally just use "*" for the allow-origin header, 
        // but Chrome (and perhaps others) won't allow you to use authentication if
        // the header is set to "*".
        // TODO: Check elsewhere to see if the origin is actually on the list of trusted domains.
        var ctx = filterContext.RequestContext.HttpContext;
        var origin = ctx.Request.Headers["Origin"];
        var allowOrigin = !string.IsNullOrWhiteSpace(origin) ? origin : "*";
        ctx.Response.AddHeader("Access-Control-Allow-Origin", allowOrigin);
        ctx.Response.AddHeader("Access-Control-Allow-Headers", "*");
        ctx.Response.AddHeader("Access-Control-Allow-Credentials", "true");
        base.OnActionExecuting(filterContext);
    }
}

How do I get first name and last name as whole name in a MYSQL query?

rtrim(lastname)+','+rtrim(firstname) as [Person Name]
from Table

the result will show lastname,firstname as one column header !

how do I get the bullet points of a <ul> to center with the text?

I found the answer today. Maybe its too late but still I think its a much better one. Check this one https://jsfiddle.net/Amar_newDev/khb2oyru/5/

Try to change the CSS code : <ul> max-width:1%; margin:auto; text-align:left; </ul>

max-width:80% or something like that.

Try experimenting you might find something new.

How to clean up R memory (without the need to restart my PC)?

I've found it helpful to go into my "tmp" folder and delete all hanging rsession files. This usually frees any memory that seems to be "stuck".

Kotlin's List missing "add", "remove", Map missing "put", etc?

Defining a List collection in Kotlin in different ways:

  • Immutable variable with immutable (read only) list:

    val users: List<User> = listOf( User("Tom", 32), User("John", 64) )
    


  • Immutable variable with mutable list:

    val users: MutableList<User> = mutableListOf( User("Tom", 32), User("John", 64) )
    

    or without initial value - empty list and without explicit variable type:

    val users = mutableListOf<User>()
    //or
    val users = ArrayList<User>()
    
    • you can add items to list:
      • users.add(anohterUser) or
      • users += anotherUser (under the hood it's users.add(anohterUser))


  • Mutable variable with immutable list:

    var users: List<User> = listOf( User("Tom", 32), User("John", 64) )
    

    or without initial value - empty list and without explicit variable type:

    var users = emptyList<User>()
    
    • NOTE: you can add* items to list:
      • users += anotherUser - *it creates new ArrayList and assigns it to users


  • Mutable variable with mutable list:

    var users: MutableList<User> = mutableListOf( User("Tom", 32), User("John", 64) )
    

    or without initial value - empty list and without explicit variable type:

    var users = emptyList<User>().toMutableList()
    //or
    var users = ArrayList<User>()
    
    • NOTE: you can add items to list:
      • users.add(anohterUser)
      • but not using users += anotherUser

        Error: Kotlin: Assignment operators ambiguity:
        public operator fun Collection.plus(element: String): List defined in kotlin.collections
        @InlineOnly public inline operator fun MutableCollection.plusAssign(element: String): Unit defined in kotlin.collections


see also: https://kotlinlang.org/docs/reference/collections.html

<meta charset="utf-8"> vs <meta http-equiv="Content-Type">

<meta charset="utf-8"> was introduced with/for HTML5.

As mentioned in the documentation, both are valid. However, <meta charset="utf-8"> is only for HTML5 (and easier to type/remember).

In due time, the old style is bound to become deprecated in the near future. I'd stick to the new <meta charset="utf-8">.

There's only one way, but up. In tech's case, that's phasing out the old (really, REALLY fast)

Documentation: HTML meta charset Attribute—W3Schools

Beginner Python Practice?

I always find it easier to learn a language in a specific problem domain. You might try looking at Django and doing the tutorial. This will give you a very light-weight intro to both Python and to a web framework (a very well-documented one) that is 100% Python.

Then do something in your field(s) of expertise -- graph generation, or whatever -- and tie that into a working framework to see if you got it right. My universe tends to be computational linguistics and there are a number of Python-based toolkits to help get you started. E.g. Natural Language Toolkit.

Just a thought.

How can I suppress the newline after a print statement?

The question asks: "How can it be done in Python 3?"

Use this construct with Python 3.x:

for item in [1,2,3,4]:
    print(item, " ", end="")

This will generate:

1  2  3  4

See this Python doc for more information:

Old: print x,           # Trailing comma suppresses newline
New: print(x, end=" ")  # Appends a space instead of a newline

--

Aside:

in addition, the print() function also offers the sep parameter that lets one specify how individual items to be printed should be separated. E.g.,

In [21]: print('this','is', 'a', 'test')  # default single space between items
this is a test

In [22]: print('this','is', 'a', 'test', sep="") # no spaces between items
thisisatest

In [22]: print('this','is', 'a', 'test', sep="--*--") # user specified separation
this--*--is--*--a--*--test

center aligning a fixed position div

Center it horizontally:

display: fixed;
top: 0; 
left: 0;
transform: translate(calc(50vw - 50%));

Center it horizontally and vertically:

display: fixed;
top: 0; 
left: 0;
transform: translate(calc(50vw - 50%), calc(50vh - 50%));

No side effect: It will not limit element's width when using margins in flexbox

How to select all textareas and textboxes using jQuery?

Password boxes are also textboxes, so if you need them too:

$("input[type='text'], textarea, input[type='password']").css({width: "90%"});

and while file-input is a bit different, you may want to include them too (eg. for visual consistency):

$("input[type='text'], textarea, input[type='password'], input[type='file']").css({width: "90%"});

How do I check if a type is a subtype OR the type of an object?

typeof(BaseClass).IsAssignableFrom(unknownType);

How do I go about adding an image into a java project with eclipse?

Place the image in a source folder, not a regular folder. That is: right-click on project -> New -> Source Folder. Place the image in that source folder. Then:

InputStream input = classLoader.getResourceAsStream("image.jpg");

Note that the path is omitted. That's because the image is directly in the root of the path. You can add folders under your source folder to break it down further if you like. Or you can put the image under your existing source folder (usually called src).

String split on new line, tab and some number of spaces

Just use .strip(), it removes all whitespace for you, including tabs and newlines, while splitting. The splitting itself can then be done with data_string.splitlines():

[s.strip() for s in data_string.splitlines()]

Output:

>>> [s.strip() for s in data_string.splitlines()]
['Name: John Smith', 'Home: Anytown USA', 'Phone: 555-555-555', 'Other Home: Somewhere Else', 'Notes: Other data', 'Name: Jane Smith', 'Misc: Data with spaces']

You can even inline the splitting on : as well now:

>>> [s.strip().split(': ') for s in data_string.splitlines()]
[['Name', 'John Smith'], ['Home', 'Anytown USA'], ['Phone', '555-555-555'], ['Other Home', 'Somewhere Else'], ['Notes', 'Other data'], ['Name', 'Jane Smith'], ['Misc', 'Data with spaces']]

Extract month and year from a zoo::yearmon object

The lubridate package is amazing for this kind of thing:

> require(lubridate)
> month(date1)
[1] 3
> year(date1)
[1] 2012

Java - Convert image to Base64

You can create a large array and then copy it to a new array using System.arrayCopy

        int contentLength = 100000000;
        byte[] byteArray = new byte[contentLength];

        BufferedInputStream inputStream = new BufferedInputStream(connection.getInputStream());
        while ((bytesRead = inputStream.read()) != -1)
        {
            byteArray[count++] = (byte)bytesRead;
        }

        byte[] destArray = new byte[count];
        System.arraycopy(byteArray, 0, destArray , 0, count);

destArray will contain the information you want

Why SpringMVC Request method 'GET' not supported?

Change

@RequestMapping(value = "/test", method = RequestMethod.POST)

To

@RequestMapping(value = "/test", method = RequestMethod.GET)

Undo a git stash

git stash list to list your stashed changes.

git stash show to see what n is in the below commands.

git stash apply to apply the most recent stash.

git stash apply stash@{n} to apply an older stash.

https://git-scm.com/book/en/v2/Git-Tools-Stashing-and-Cleaning

How can I get the image url in a Wordpress theme?

I strongly recommend the following:

<img src="<?php echo get_stylesheet_directory_uri(); ?>/img-folder/your_image.jpg">

It works for almost any file you want to add to your wordpress project, be it image or CSS.

Retrieve WordPress root directory path?

This an old question, but I have a new answer. This single line will return the path inside a template: :)

$wp_root_path = str_replace('/wp-content/themes', '', get_theme_root());

list.clear() vs list = new ArrayList<Integer>();

List.clear would remove the elements without reducing the capacity of the list.

groovy:000> mylist = [1,2,3,4,5,6,7,8,9,10,11,12]
===> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
groovy:000> mylist.elementData.length
===> 12
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@19d6af
groovy:000> mylist.clear()
===> null
groovy:000> mylist.elementData.length
===> 12
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@19d6af
groovy:000> mylist = new ArrayList();
===> []
groovy:000> mylist.elementData
===> [Ljava.lang.Object;@2bfdff
groovy:000> mylist.elementData.length
===> 10

Here mylist got cleared, the references to the elements held by it got nulled out, but it keeps the same backing array. Then mylist was reinitialized and got a new backing array, the old one got GCed. So one way holds onto memory, the other one throws out its memory and gets reallocated from scratch (with the default capacity). Which is better depends on whether you want to reduce garbage-collection churn or minimize the current amount of unused memory. Whether the list sticks around long enough to be moved out of Eden might be a factor in deciding which is faster (because that might make garbage-collecting it more expensive).

SQLAlchemy: What's the difference between flush() and commit()?

commit () records these changes in the database. flush () is always called as part of the commit () (1) call. When you use a Session object to query a database, the query returns results from both the database and the reddened parts of the unrecorded transaction it is performing.

Referencing a string in a string array resource with xml

Unfortunately:

  • It seems you can not reference a single item from an array in values/arrays.xml with XML. Of course you can in Java, but not XML. There's no information on doing so in the Android developer reference, and I could not find any anywhere else.

  • It seems you can't use an array as a key in the preferences layout. Each key has to be a single value with it's own key name.

What I want to accomplish: I want to be able to loop through the 17 preferences, check if the item is checked, and if it is, load the string from the string array for that preference name.

Here's the code I was hoping would complete this task:

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());  
ArrayAdapter<String> itemsArrayList = new ArrayAdapter<String>(getBaseContext(),   android.R.layout.simple_list_item_1);  
String[] itemNames = getResources().getStringArray(R.array.itemNames_array);  


for (int i = 0; i < 16; i++) {  
    if (prefs.getBoolean("itemKey[i]", true)) {  
        itemsArrayList.add(itemNames[i]);  
    }  
} 

What I did:

  • I set a single string for each of the items, and referenced the single strings in the . I use the single string reference for the preferences layout checkbox titles, and the array for my loop.

  • To loop through the preferences, I just named the keys like key1, key2, key3, etc. Since you reference a key with a string, you have the option to "build" the key name at runtime.

Here's the new code:

for (int i = 0; i < 16; i++) {  
        if (prefs.getBoolean("itemKey" + String.valueOf(i), true)) {  
        itemsArrayList.add(itemNames[i]);  
    }  
}

Android XXHDPI resources

The resolution is 480 dpi, the launcher icon is 144*144px all is scaled 3x respect to mdpi (so called "base", "baseline" or "normal") sizes.

Python string to unicode

Unicode escapes only work in unicode strings, so this

 a="\u2026"

is actually a string of 6 characters: '\', 'u', '2', '0', '2', '6'.

To make unicode out of this, use decode('unicode-escape'):

a="\u2026"
print repr(a)
print repr(a.decode('unicode-escape'))

## '\\u2026'
## u'\u2026'

Disable hover effects on mobile browsers

I take it from your question that your hover effect changes the content of your page. In that case, my advice is to:

  • Add hover effects on touchstart and mouseenter.
  • Remove hover effects on mouseleave, touchmove and click.

Alternatively, you can edit your page that there is no content change.

Background

In order to simulate a mouse, browsers such as Webkit mobile fire the following events if a user touches and releases a finger on touch screen (like iPad) (source: Touch And Mouse on html5rocks.com):

  1. touchstart
  2. touchmove
  3. touchend
  4. 300ms delay, where the browser makes sure this is a single tap, not a double tap
  5. mouseover
  6. mouseenter
    • Note: If a mouseover, mouseenter or mousemove event changes the page content, the following events are never fired.
  7. mousemove
  8. mousedown
  9. mouseup
  10. click

It does not seem possible to simply tell the webbrowser to skip the mouse events.

What's worse, if a mouseover event changes the page content, the click event is never fired, as explained on Safari Web Content Guide - Handling Events, in particular figure 6.4 in One-Finger Events. What exactly a "content change" is, will depend on browser and version. I've found that for iOS 7.0, a change in background color is not (or no longer?) a content change.

Solution Explained

To recap:

  • Add hover effects on touchstart and mouseenter.
  • Remove hover effects on mouseleave, touchmove and click.

Note that there is no action on touchend!

This clearly works for mouse events: mouseenter and mouseleave (slightly improved versions of mouseover and mouseout) are fired, and add and remove the hover.

If the user actually clicks a link, the hover effect is also removed. This ensure that it is removed if the user presses the back button in the web browser.

This also works for touch events: on touchstart the hover effect is added. It is '''not''' removed on touchend. It is added again on mouseenter, and since this causes no content changes (it was already added), the click event is also fired, and the link is followed without the need for the user to click again!

The 300ms delay that a browser has between a touchstart event and click is actually put in good use because the hover effect will be shown during this short time.

If the user decides to cancel the click, a move of the finger will do so just as normal. Normally, this is a problem since no mouseleave event is fired, and the hover effect remains in place. Thankfully, this can easily be fixed by removing the hover effect on touchmove.

That's it!

Note that it is possible to remove the 300ms delay, for example using the FastClick library, but this is out of scope for this question.

Alternative Solutions

I've found the following problems with the following alternatives:

  • browser detection: Extremely prone to errors. Assumes that a device has either mouse or touch, while a combination of both will become more and more common when touch displays prolifirate.
  • CSS media detection: The only CSS-only solution I'm aware of. Still prone to errors, and still assumes that a device has either mouse or touch, while both are possible.
  • Emulate the click event in touchend: This will incorrectly follow the link, even if the user only wanted to scroll or zoom, without the intention of actually clicking the link.
  • Use a variable to suppress mouse events: This set a variable in touchend that is used as a if-condition in subsequent mouse events to prevents state changes at that point in time. The variable is reset in the click event. See Walter Roman's answer on this page. This is a decent solution if you really don't want a hover effect on touch interfaces. Unfortunately, this does not work if a touchend is fired for another reason and no click event is fired (e.g. the user scrolled or zoomed), and is subsequently trying to following the link with a mouse (i.e on a device with both mouse and touch interface).

Further Reading

How to extend an existing JavaScript array with another array, without creating a new array

If you want to use jQuery, there is $.merge()

Example:

a = [1, 2];
b = [3, 4, 5];
$.merge(a,b);

Result: a = [1, 2, 3, 4, 5]

How to overlay one div over another div

Here is a simple example to bring an overlay effect with a loading icon over another div.

<style>
    #overlay {
        position: absolute;
        width: 100%;
        height: 100%;
        background: black url('icons/loading.gif') center center no-repeat; /* Make sure the path and a fine named 'loading.gif' is there */
        background-size: 50px;
        z-index: 1;
        opacity: .6;
    }
    .wraper{
        position: relative;
        width:400px;  /* Just for testing, remove width and height if you have content inside this div */
        height:500px; /* Remove this if you have content inside */
    }
</style>

<h2>The overlay tester</h2>
<div class="wraper">
    <div id="overlay"></div>
    <h3>Apply the overlay over this div</h3>
</div>

Try it here: http://jsbin.com/fotozolucu/edit?html,css,output

How to bind RadioButtons to an enum?

This work for Checkbox too.

public class EnumToBoolConverter:IValueConverter
{
    private int val;
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        int intParam = (int)parameter;
        val = (int)value;

        return ((intParam & val) != 0);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        val ^= (int)parameter;
        return Enum.Parse(targetType, val.ToString());
    }
}

Binding a single enum to multiple checkboxes.

How do I fix a merge conflict due to removal of a file in a branch?

If you are using Git Gui on windows,

  1. Abort the merge
  2. Make sure you are on your target branch
  3. Delete the conflicting file from explorer
  4. Rescan for changes in Git Gui (F5)
  5. Notice that conflicting file is deleted
  6. Select Stage Changed Files To Commit (Ctrl-I) from Commit menu
  7. Enter a commit comment like "deleted conflicting file"
  8. Commit (ctrl-enter)
  9. Now if you restart the merge it will (hopefully) work.

How to convert SSH keypairs generated using PuTTYgen (Windows) into key-pairs used by ssh-agent and Keychain (Linux)

I recently had this problem as I was moving from Putty for Linux to Remmina for Linux. So I have a lot of PPK files for Putty in my .putty directory as I've been using it's for 8 years. For this I used a simple for command for bash shell to do all files:

cd ~/.putty
for X in *.ppk; do puttygen $X -L > ~/.ssh/$(echo $X | sed 's,./,,' | sed 's/.ppk//g').pub; puttygen $X -O private-openssh -o ~/.ssh/$(echo $X | sed 's,./,,' | sed 's/.ppk//g').pvk; done;

Very quick and to the point, got the job done for all files that putty had. If it finds a key with a password it will stop and ask for the password for that key first and then continue.

Using quotation marks inside quotation marks

in Python 3.2.2 on Windows,

print(""""A word that needs quotation marks" """) 

is ok. I think it is the enhancement of Python interpretor.

Python Requests library redirect new url

For python3.5, you can use the following code:

import urllib.request
res = urllib.request.urlopen(starturl)
finalurl = res.geturl()
print(finalurl)

Accessing clicked element in angularjs

While AngularJS allows you to get a hand on a click event (and thus a target of it) with the following syntax (note the $event argument to the setMaster function; documentation here: http://docs.angularjs.org/api/ng.directive:ngClick):

function AdminController($scope) {    
  $scope.setMaster = function(obj, $event){
    console.log($event.target);
  }
}

this is not very angular-way of solving this problem. With AngularJS the focus is on the model manipulation. One would mutate a model and let AngularJS figure out rendering.

The AngularJS-way of solving this problem (without using jQuery and without the need to pass the $event argument) would be:

<div ng-controller="AdminController">
    <ul class="list-holder">
        <li ng-repeat="section in sections" ng-class="{active : isSelected(section)}">
            <a ng-click="setMaster(section)">{{section.name}}</a>
        </li>
    </ul>
    <hr>
    {{selected | json}}
</div>

where methods in the controller would look like this:

$scope.setMaster = function(section) {
    $scope.selected = section;
}

$scope.isSelected = function(section) {
    return $scope.selected === section;
}

Here is the complete jsFiddle: http://jsfiddle.net/pkozlowski_opensource/WXJ3p/15/

What is __main__.py?

Some of the answers here imply that given a "package" directory (with or without an explicit __init__.py file), containing a __main__.py file, there is no difference between running that directory with the -m switch or without.

The big difference is that without the -m switch, the "package" directory is first added to the path (i.e. sys.path), and then the files are run normally, without package semantics.

Whereas with the -m switch, package semantics (including relative imports) are honoured, and the package directory itself is never added to the system path.

This is a very important distinction, both in terms of whether relative imports will work or not, but more importantly in terms of dictating what will be imported in the case of unintended shadowing of system modules.


Example:

Consider a directory called PkgTest with the following structure

:~/PkgTest$ tree
.
+-- pkgname
¦   +-- __main__.py
¦   +-- secondtest.py
¦   +-- testmodule.py
+-- testmodule.py

where the __main__.py file has the following contents:

:~/PkgTest$ cat pkgname/__main__.py
import os
print( "Hello from pkgname.__main__.py. I am the file", os.path.abspath( __file__ ) )
print( "I am being accessed from", os.path.abspath( os.curdir ) )
from  testmodule import main as firstmain;     firstmain()
from .secondtest import main as secondmain;    secondmain()

(with the other files defined similarly with similar printouts).

If you run this without the -m switch, this is what you'll get. Note that the relative import fails, but more importantly note that the wrong testmodule has been chosen (i.e. relative to the working directory):

:~/PkgTest$ python3 pkgname
Hello from pkgname.__main__.py. I am the file ~/PkgTest/pkgname/__main__.py
I am being accessed from ~/PkgTest
Hello from testmodule.py. I am the file ~/PkgTest/pkgname/testmodule.py
I am being accessed from ~/PkgTest
Traceback (most recent call last):
  File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "pkgname/__main__.py", line 10, in <module>
    from .secondtest import main as secondmain
ImportError: attempted relative import with no known parent package

Whereas with the -m switch, you get what you (hopefully) expected:

:~/PkgTest$ python3 -m pkgname
Hello from pkgname.__main__.py. I am the file ~/PkgTest/pkgname/__main__.py
I am being accessed from ~/PkgTest
Hello from testmodule.py. I am the file ~/PkgTest/testmodule.py
I am being accessed from ~/PkgTest
Hello from secondtest.py. I am the file ~/PkgTest/pkgname/secondtest.py
I am being accessed from ~/PkgTest


Note: In my honest opinion, running without -m should be avoided. In fact I would go further and say that I would create any executable packages in such a way that they would fail unless run via the -m switch.

In other words, I would only import from 'in-package' modules explicitly via 'relative imports', assuming that all other imports represent system modules. If someone attempts to run your package without the -m switch, the relative import statements will throw an error, instead of silently running the wrong module.

Unit testing with Spring Security

After quite a lot of work I was able to reproduce the desired behavior. I had emulated the login through MockMvc. It is too heavy for most unit tests but helpful for integration tests.

Of course I am willing to see those new features in Spring Security 4.0 that will make our testing easier.

package [myPackage]

import static org.junit.Assert.*;

import javax.inject.Inject;
import javax.servlet.http.HttpSession;

import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.runners.Enclosed;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.FilterChainProxy;
import org.springframework.security.web.context.HttpSessionSecurityContextRepository;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;

@ContextConfiguration(locations={[my config file locations]})
@WebAppConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public static class getUserConfigurationTester{

    private MockMvc mockMvc;

    @Autowired
    private FilterChainProxy springSecurityFilterChain;

    @Autowired
    private MockHttpServletRequest request;

    @Autowired
    private WebApplicationContext webappContext;

    @Before  
    public void init() {  
        mockMvc = MockMvcBuilders.webAppContextSetup(webappContext)
                    .addFilters(springSecurityFilterChain)
                    .build();
    }  


    @Test
    public void testTwoReads() throws Exception{                        

    HttpSession session  = mockMvc.perform(post("/j_spring_security_check")
                        .param("j_username", "admin_001")
                        .param("j_password", "secret007"))
                        .andDo(print())
                        .andExpect(status().isMovedTemporarily())
                        .andExpect(redirectedUrl("/index"))
                        .andReturn()
                        .getRequest()
                        .getSession();

    request.setSession(session);

    SecurityContext securityContext = (SecurityContext)   session.getAttribute(HttpSessionSecurityContextRepository.SPRING_SECURITY_CONTEXT_KEY);

    SecurityContextHolder.setContext(securityContext);

        // Your test goes here. User is logged with 
}

Click event on select option element in chrome

The easy way to change the select, and update it is this.

// BY id
$('#select_element_selector').val('value').change();

another example:

//By tag
$('[name=selectxD]').val('value').change();

another example:

$("#select_element_selector").val('value').trigger('chosen:updated');

What's the difference between [ and [[ in Bash?

The most important difference will be the clarity of your code. Yes, yes, what's been said above is true, but [[ ]] brings your code in line with what you would expect in high level languages, especially in regards to AND (&&), OR (||), and NOT (!) operators. Thus, when you move between systems and languages you will be able to interpret script faster which makes your life easier. Get the nitty gritty from a good UNIX/Linux reference. You may find some of the nitty gritty to be useful in certain circumstances, but you will always appreciate clear code! Which script fragment would you rather read? Even out of context, the first choice is easier to read and understand.


if [[ -d $newDir && -n $(echo $newDir | grep "^${webRootParent}") && -n $(echo $newDir | grep '/$') ]]; then ...

or

if [ -d "$newDir" -a -n "$(echo "$newDir" | grep "^${webRootParent}")" -a -n "$(echo "$newDir" | grep '/$')" ]; then ...

Android selector & text color

I always used the above solution without searching more after this. ;-)

However, today I came across something and thought of sharing it. :)

This feature is indeed available from API 1 and is called as ColorStateList, where we can supply a color to various states of Widgets (as we already know).

It is also very well documented, here.

How to resolve ORA-011033: ORACLE initialization or shutdown in progress

The issue can also be due to lack of hard drive space. The installation will succeed but on startup, oracle won't be able to create the required files and will fail with the same above error message.

Errno 10060] A connection attempt failed because the connected party did not properly respond after a period of time

As ping works, but telnetto port 80 does not, the HTTP port 80 is closed on your machine. I assume that your browser's HTTP connection goes through a proxy (as browsing works, how else would you read stackoverflow?). You need to add some code to your python program, that handles the proxy, like described here:

Using an HTTP PROXY - Python

How can I make Bootstrap columns all the same height?

I searched for a solution to the same problem, and found one just worked !! - with almost no extra code..

see https://medium.com/wdstack/bootstrap-equal-height-columns-d07bc934eb27 for a good disuccuion, and with the resposne you want in the bottom, with a link.

https://www.codeply.com/go/EskIjvun4B

this was the correct responsive way to for me... a quote: ... 3 — Use flexbox (best!)

As of 2017, the best (and easiest) way to make equal height columns in a responsive design is using CSS3 flexbox.

.row.display-flex {
  display: flex;
  flex-wrap: wrap;
}
.row.display-flex > [class*='col-'] {
  display: flex;
  flex-direction: column;
}

and simply use:

div class="container">
   <div class="row display-flex .... etc..

Is there a difference between PhoneGap and Cordova commands?

http://phonegap.com/blog/2012/03/19/phonegap-cordova-and-whate28099s-in-a-name/

I think this url explains what you need. Phonegap is built on Apache Cordova nothing else. You can think of Apache Cordova as the engine that powers PhoneGap. Over time, the PhoneGap distribution may contain additional tools and thats why they differ in command But they do same thing.

EDIT: Extra info added as its about command difference and what phonegap can do while apache cordova can't or viceversa

First of command line option of PhoneGap

http://docs.phonegap.com/en/edge/guide_cli_index.md.html

Apache Cordova Options http://cordova.apache.org/docs/en/3.0.0/guide_cli_index.md.html#The%20Command-line%20Interface

  1. As almost most of commands are similar. There are few differences (Note: No difference in Codebase)

  2. Adobe can add additional features to PhoneGap so that will not be in Cordova ,Eg: Building applications remotely for that you need to have account on https://build.phonegap.com

  3. Though For local builds phonegap cli uses cordova cli (Link to check: https://github.com/phonegap/phonegap-cli/blob/master/lib/phonegap/util/platform.js)

    Platform Environment Names. Mapping:

    'local' => cordova-cli

    'remote' => PhoneGap/Build

Also from following repository: Modules which requires cordova are:

build
create
install
local install
local plugin add , list , remove
run
mode
platform update
run

Which dont include cordova:

remote build
remote install
remote login,logout
remote run
serve

How do I find the version of Apache running without access to the command line?

Your best option is through PHP: All version requests from the client side cannot be trusted since your Apache could be configured with ServerTokens Prod and ServerSignature Off. See: http://www.petefreitag.com/item/419.cfm

PHP - remove all non-numeric characters from a string

Use \D to match non-digit characters.

preg_replace('~\D~', '', $str);

Reimport a module in python while interactive

Actually, in Python 3 the module imp is marked as DEPRECATED. Well, at least that's true for 3.4.

Instead the reload function from the importlib module should be used:

https://docs.python.org/3/library/importlib.html#importlib.reload

But be aware that this library had some API-changes with the last two minor versions.

What is the proper way to re-attach detached objects in Hibernate?

Entity states

JPA defines the following entity states:

New (Transient)

A newly created object that hasn’t ever been associated with a Hibernate Session (a.k.a Persistence Context) and is not mapped to any database table row is considered to be in the New (Transient) state.

To become persisted we need to either explicitly call the EntityManager#persist method or make use of the transitive persistence mechanism.

Persistent (Managed)

A persistent entity has been associated with a database table row and it’s being managed by the currently running Persistence Context. Any change made to such an entity is going to be detected and propagated to the database (during the Session flush-time).

With Hibernate, we no longer have to execute INSERT/UPDATE/DELETE statements. Hibernate employs a transactional write-behind working style and changes are synchronized at the very last responsible moment, during the current Session flush-time.

Detached

Once the currently running Persistence Context is closed all the previously managed entities become detached. Successive changes will no longer be tracked and no automatic database synchronization is going to happen.

Entity state transitions

You can change the entity state using various methods defined by the EntityManager interface.

To understand the JPA entity state transitions better, consider the following diagram:

JPA entity state transitions

When using JPA, to reassociate a detached entity to an active EntityManager, you can use the merge operation.

When using the native Hibernate API, apart from merge, you can reattach a detached entity to an active Hibernate Sessionusing the update methods, as demonstrated by the following diagram:

Hibernate entity state transitions

Merging a detached entity

The merge is going to copy the detached entity state (source) to a managed entity instance (destination).

Consider we have persisted the following Book entity, and now the entity is detached as the EntityManager that was used to persist the entity got closed:

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setIsbn("978-9730228236")
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");
 
    entityManager.persist(book);
 
    return book;
});

While the entity is in the detached state, we modify it as follows:

_book.setTitle(
    "High-Performance Java Persistence, 2nd edition"
);

Now, we want to propagate the changes to the database, so we can call the merge method:

doInJPA(entityManager -> {
    Book book = entityManager.merge(_book);
 
    LOGGER.info("Merging the Book entity");
 
    assertFalse(book == _book);
});

And Hibernate is going to execute the following SQL statements:

SELECT
    b.id,
    b.author AS author2_0_,
    b.isbn AS isbn3_0_,
    b.title AS title4_0_
FROM
    book b
WHERE
    b.id = 1
 
-- Merging the Book entity
 
UPDATE
    book
SET
    author = 'Vlad Mihalcea',
    isbn = '978-9730228236',
    title = 'High-Performance Java Persistence, 2nd edition'
WHERE
    id = 1

If the merging entity has no equivalent in the current EntityManager, a fresh entity snapshot will be fetched from the database.

Once there is a managed entity, JPA copies the state of the detached entity onto the one that is currently managed, and during the Persistence Context flush, an UPDATE will be generated if the dirty checking mechanism finds that the managed entity has changed.

So, when using merge, the detached object instance will continue to remain detached even after the merge operation.

Reattaching a detached entity

Hibernate, but not JPA supports reattaching through the update method.

A Hibernate Session can only associate one entity object for a given database row. This is because the Persistence Context acts as an in-memory cache (first level cache) and only one value (entity) is associated with a given key (entity type and database identifier).

An entity can be reattached only if there is no other JVM object (matching the same database row) already associated with the current Hibernate Session.

Considering we have persisted the Book entity and that we modified it when the Book entity was in the detached state:

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setIsbn("978-9730228236")
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");
 
    entityManager.persist(book);
 
    return book;
});
      
_book.setTitle(
    "High-Performance Java Persistence, 2nd edition"
);

We can reattach the detached entity like this:

doInJPA(entityManager -> {
    Session session = entityManager.unwrap(Session.class);
 
    session.update(_book);
 
    LOGGER.info("Updating the Book entity");
});

And Hibernate will execute the following SQL statement:

-- Updating the Book entity
 
UPDATE
    book
SET
    author = 'Vlad Mihalcea',
    isbn = '978-9730228236',
    title = 'High-Performance Java Persistence, 2nd edition'
WHERE
    id = 1

The update method requires you to unwrap the EntityManager to a Hibernate Session.

Unlike merge, the provided detached entity is going to be reassociated with the current Persistence Context and an UPDATE is scheduled during flush whether the entity has modified or not.

To prevent this, you can use the @SelectBeforeUpdate Hibernate annotation which will trigger a SELECT statement that fetched loaded state which is then used by the dirty checking mechanism.

@Entity(name = "Book")
@Table(name = "book")
@SelectBeforeUpdate
public class Book {
 
    //Code omitted for brevity
}

Beware of the NonUniqueObjectException

One problem that can occur with update is if the Persistence Context already contains an entity reference with the same id and of the same type as in the following example:

Book _book = doInJPA(entityManager -> {
    Book book = new Book()
    .setIsbn("978-9730228236")
    .setTitle("High-Performance Java Persistence")
    .setAuthor("Vlad Mihalcea");
 
    Session session = entityManager.unwrap(Session.class);
    session.saveOrUpdate(book);
 
    return book;
});
 
_book.setTitle(
    "High-Performance Java Persistence, 2nd edition"
);
 
try {
    doInJPA(entityManager -> {
        Book book = entityManager.find(
            Book.class,
            _book.getId()
        );
 
        Session session = entityManager.unwrap(Session.class);
        session.saveOrUpdate(_book);
    });
} catch (NonUniqueObjectException e) {
    LOGGER.error(
        "The Persistence Context cannot hold " +
        "two representations of the same entity",
        e
    );
}

Now, when executing the test case above, Hibernate is going to throw a NonUniqueObjectException because the second EntityManager already contains a Book entity with the same identifier as the one we pass to update, and the Persistence Context cannot hold two representations of the same entity.

org.hibernate.NonUniqueObjectException:
    A different object with the same identifier value was already associated with the session : [com.vladmihalcea.book.hpjp.hibernate.pc.Book#1]
    at org.hibernate.engine.internal.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:651)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:284)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:227)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:92)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
    at org.hibernate.internal.SessionImpl.fireSaveOrUpdate(SessionImpl.java:682)
    at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:674)

Conclusion

The merge method is to be preferred if you are using optimistic locking as it allows you to prevent lost updates.

The update is good for batch updates as it can prevent the additional SELECT statement generated by the merge operation, therefore reducing the batch update execution time.

How to decorate a class?

I'd agree inheritance is a better fit for the problem posed.

I found this question really handy though on decorating classes, thanks all.

Here's another couple of examples, based on other answers, including how inheritance affects things in Python 2.7, (and @wraps, which maintains the original function's docstring, etc.):

def dec(klass):
    old_foo = klass.foo
    @wraps(klass.foo)
    def decorated_foo(self, *args ,**kwargs):
        print('@decorator pre %s' % msg)
        old_foo(self, *args, **kwargs)
        print('@decorator post %s' % msg)
    klass.foo = decorated_foo
    return klass

@dec  # No parentheses
class Foo...

Often you want to add parameters to your decorator:

from functools import wraps

def dec(msg='default'):
    def decorator(klass):
        old_foo = klass.foo
        @wraps(klass.foo)
        def decorated_foo(self, *args ,**kwargs):
            print('@decorator pre %s' % msg)
            old_foo(self, *args, **kwargs)
            print('@decorator post %s' % msg)
        klass.foo = decorated_foo
        return klass
    return decorator

@dec('foo decorator')  # You must add parentheses now, even if they're empty
class Foo(object):
    def foo(self, *args, **kwargs):
        print('foo.foo()')

@dec('subfoo decorator')
class SubFoo(Foo):
    def foo(self, *args, **kwargs):
        print('subfoo.foo() pre')
        super(SubFoo, self).foo(*args, **kwargs)
        print('subfoo.foo() post')

@dec('subsubfoo decorator')
class SubSubFoo(SubFoo):
    def foo(self, *args, **kwargs):
        print('subsubfoo.foo() pre')
        super(SubSubFoo, self).foo(*args, **kwargs)
        print('subsubfoo.foo() post')

SubSubFoo().foo()

Outputs:

@decorator pre subsubfoo decorator
subsubfoo.foo() pre
@decorator pre subfoo decorator
subfoo.foo() pre
@decorator pre foo decorator
foo.foo()
@decorator post foo decorator
subfoo.foo() post
@decorator post subfoo decorator
subsubfoo.foo() post
@decorator post subsubfoo decorator

I've used a function decorator, as I find them more concise. Here's a class to decorate a class:

class Dec(object):

    def __init__(self, msg):
        self.msg = msg

    def __call__(self, klass):
        old_foo = klass.foo
        msg = self.msg
        def decorated_foo(self, *args, **kwargs):
            print('@decorator pre %s' % msg)
            old_foo(self, *args, **kwargs)
            print('@decorator post %s' % msg)
        klass.foo = decorated_foo
        return klass

A more robust version that checks for those parentheses, and works if the methods don't exist on the decorated class:

from inspect import isclass

def decorate_if(condition, decorator):
    return decorator if condition else lambda x: x

def dec(msg):
    # Only use if your decorator's first parameter is never a class
    assert not isclass(msg)

    def decorator(klass):
        old_foo = getattr(klass, 'foo', None)

        @decorate_if(old_foo, wraps(klass.foo))
        def decorated_foo(self, *args ,**kwargs):
            print('@decorator pre %s' % msg)
            if callable(old_foo):
                old_foo(self, *args, **kwargs)
            print('@decorator post %s' % msg)

        klass.foo = decorated_foo
        return klass

    return decorator

The assert checks that the decorator has not been used without parentheses. If it has, then the class being decorated is passed to the msg parameter of the decorator, which raises an AssertionError.

@decorate_if only applies the decorator if condition evaluates to True.

The getattr, callable test, and @decorate_if are used so that the decorator doesn't break if the foo() method doesn't exist on the class being decorated.

How to convert JSON object to JavaScript array?

This will solve the problem:

const json_data = {"2013-01-21":1,"2013-01-22":7};

const arr = Object.keys(json_data).map((key) => [key, json_data[key]]);

console.log(arr);

Or using Object.entries() method:

console.log(Object.entries(json_data));

In both the cases, output will be:

/* output: 
[['2013-01-21', 1], ['2013-01-22', 7]]
*/

Checkout one file from Subversion

Since none of the other answers worked for me I did it using this hack:

$ cd /yourfolder
svn co https://path-to-folder-which-has-your-files/ --depth files

This will create a new local folder which has only the files from the remote path. Then you can do a symbolic link to the files you want to have here.

Encrypt Password in Configuration Files?

A simple way of doing this is to use Password Based Encryption in Java. This allows you to encrypt and decrypt a text by using a password.

This basically means initializing a javax.crypto.Cipher with algorithm "AES/CBC/PKCS5Padding" and getting a key from javax.crypto.SecretKeyFactory with the "PBKDF2WithHmacSHA512" algorithm.

Here is a code example (updated to replace the less secure MD5-based variant):

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.AlgorithmParameters;
import java.security.GeneralSecurityException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

public class ProtectedConfigFile {

    public static void main(String[] args) throws Exception {
        String password = System.getProperty("password");
        if (password == null) {
            throw new IllegalArgumentException("Run with -Dpassword=<password>");
        }

        // The salt (probably) can be stored along with the encrypted data
        byte[] salt = new String("12345678").getBytes();

        // Decreasing this speeds down startup time and can be useful during testing, but it also makes it easier for brute force attackers
        int iterationCount = 40000;
        // Other values give me java.security.InvalidKeyException: Illegal key size or default parameters
        int keyLength = 128;
        SecretKeySpec key = createSecretKey(password.toCharArray(),
                salt, iterationCount, keyLength);

        String originalPassword = "secret";
        System.out.println("Original password: " + originalPassword);
        String encryptedPassword = encrypt(originalPassword, key);
        System.out.println("Encrypted password: " + encryptedPassword);
        String decryptedPassword = decrypt(encryptedPassword, key);
        System.out.println("Decrypted password: " + decryptedPassword);
    }

    private static SecretKeySpec createSecretKey(char[] password, byte[] salt, int iterationCount, int keyLength) throws NoSuchAlgorithmException, InvalidKeySpecException {
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA512");
        PBEKeySpec keySpec = new PBEKeySpec(password, salt, iterationCount, keyLength);
        SecretKey keyTmp = keyFactory.generateSecret(keySpec);
        return new SecretKeySpec(keyTmp.getEncoded(), "AES");
    }

    private static String encrypt(String property, SecretKeySpec key) throws GeneralSecurityException, UnsupportedEncodingException {
        Cipher pbeCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        pbeCipher.init(Cipher.ENCRYPT_MODE, key);
        AlgorithmParameters parameters = pbeCipher.getParameters();
        IvParameterSpec ivParameterSpec = parameters.getParameterSpec(IvParameterSpec.class);
        byte[] cryptoText = pbeCipher.doFinal(property.getBytes("UTF-8"));
        byte[] iv = ivParameterSpec.getIV();
        return base64Encode(iv) + ":" + base64Encode(cryptoText);
    }

    private static String base64Encode(byte[] bytes) {
        return Base64.getEncoder().encodeToString(bytes);
    }

    private static String decrypt(String string, SecretKeySpec key) throws GeneralSecurityException, IOException {
        String iv = string.split(":")[0];
        String property = string.split(":")[1];
        Cipher pbeCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        pbeCipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(base64Decode(iv)));
        return new String(pbeCipher.doFinal(base64Decode(property)), "UTF-8");
    }

    private static byte[] base64Decode(String property) throws IOException {
        return Base64.getDecoder().decode(property);
    }
}

One problem remains: Where should you store the password that you use to encrypt the passwords? You can store it in the source file and obfuscate it, but it's not too hard to find it again. Alternatively, you can give it as a system property when you start the Java process (-DpropertyProtectionPassword=...).

The same issue remains if you use the KeyStore, which also is protected by a password. Basically, you will need to have one master password somewhere, and it's pretty hard to protect.

How to clone a Date object?

Use the Date object's getTime() method, which returns the number of milliseconds since 1 January 1970 00:00:00 UTC (epoch time):

var date = new Date();
var copiedDate = new Date(date.getTime());

In Safari 4, you can also write:

var date = new Date();
var copiedDate = new Date(date);

...but I'm not sure whether this works in other browsers. (It seems to work in IE8).

Could not open a connection to your authentication agent

Instead of using $ ssh-agent -s, I used $ eval `ssh-agent -s` to solve this issue.

Here is what I performed step by step (step 2 onwards on GitBash):

  1. Cleaned up my .ssh folder at C:\user\<username>\.ssh\
  2. Generated a new SSH key
    $ ssh-keygen -t rsa -b 4096 -C "[email protected]"
  3. Check if any process id(ssh agent) is already running.
    $ ps aux | grep ssh
  4. (Optional) If found any in step 3, kill those
    $ kill <pids>
  5. Started the ssh agent
    $ eval `ssh-agent -s`
  6. Added ssh key generated in step 2 to ssh agent
    $ ssh-add ~/.ssh/id_rsa

Android studio doesn't list my phone under "Choose Device"

Why do 64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows?

System32 is where Windows historically placed all 32bit DLLs, and System was for the 16bit DLLs. When microsoft created the 64 bit OS, everyone I know of expected the files to reside under System64, but Microsoft decided it made more sense to put 64bit files under System32. The only reasoning I have been able to find, is that they wanted everything that was 32bit to work in a 64bit Windows w/o having to change anything in the programs -- just recompile, and it's done. The way they solved this, so that 32bit applications could still run, was to create a 32bit windows subsystem called Windows32 On Windows64. As such, the acronym SysWOW64 was created for the System directory of the 32bit subsystem. The Sys is short for System, and WOW64 is short for Windows32OnWindows64.
Since windows 16 is already segregated from Windows 32, there was no need for a Windows 16 On Windows 64 equivalence. Within the 32bit subsystem, when a program goes to use files from the system32 directory, they actually get the files from the SysWOW64 directory. But the process is flawed.

It's a horrible design. And in my experience, I had to do a lot more changes for writing 64bit applications, that simply changing the System32 directory to read System64 would have been a very small change, and one that pre-compiler directives are intended to handle.

Python pandas: fill a dataframe row by row

My approach was, but I can't guarantee that this is the fastest solution.

df = pd.DataFrame(columns=["firstname", "lastname"])
df = df.append({
     "firstname": "John",
     "lastname":  "Johny"
      }, ignore_index=True)

How to use particular CSS styles based on screen size / device

Detection is automatic. You must specify what css can be used for each screen resolution:

/* for all screens, use 14px font size */
body {  
    font-size: 14px;    
}
/* responsive, form small screens, use 13px font size */
@media (max-width: 479px) {
    body {
        font-size: 13px;
    }
}

How to scale a UIImageView proportionally?

imageView.contentMode = UIViewContentModeScaleAspectFill;
imageView.clipsToBounds = YES;

Is there a way to change the spacing between legend items in ggplot2?

From Koshke's work on ggplot2 and his blog (Koshke's blog)

... + theme(legend.key.height=unit(3,"line")) # Change 3 to X
... + theme(legend.key.width=unit(3,"line")) # Change 3 to X

Type theme_get() in the console to see other editable legend attributes.

How to call on a function found on another file?

You can use header files.

Good practice.

You can create a file called player.h declare all functions that are need by other cpp files in that header file and include it when needed.

player.h

#ifndef PLAYER_H    // To make sure you don't declare the function more than once by including the header multiple times.
#define PLAYER_H

#include "stdafx.h"
#include <SFML/Graphics.hpp>

int playerSprite();

#endif

player.cpp

#include "player.h"  // player.h must be in the current directory. or use relative or absolute path to it. e.g #include "include/player.h"

int playerSprite(){
    sf::Texture Texture;
    if(!Texture.loadFromFile("player.png")){
        return 1;
    }
    sf::Sprite Sprite;
    Sprite.setTexture(Texture);
    return 0;
}

main.cpp

#include "stdafx.h"
#include <SFML/Graphics.hpp>
#include "player.h"            //Here. Again player.h must be in the current directory. or use relative or absolute path to it.

int main()
{
    // ...
    int p = playerSprite();  
    //...

Not such a good practice but works for small projects. declare your function in main.cpp

#include "stdafx.h"
#include <SFML/Graphics.hpp>
// #include "player.cpp"


int playerSprite();  // Here

int main()
{
    // ...   
    int p = playerSprite();  
    //...

Apache - MySQL Service detected with wrong path. / Ports already in use

To delete existing service is not good solution for me, because on port 3306 run MySQL, which need other service. But it is possible to run two MySQL services at one time (one with other name and port). I found the solution here: http://emjaywebdesigns.com/xampp-and-multiple-instances-of-mysql-on-windows/

Here is my modified setting: Edit your “my.ini” file in c:\xampp\mysql\bin\ Change all default 3306 port entries to a new value 3308

edit your “php.ini” in c:\xampp\php and replace 3306 by 3308

Create the service entry - in Windows command line type

sc.exe create "mysqlweb" binPath= "C:\xampp\mysql\bin\mysqld.exe --defaults-file=c:\xampp\mysql\bin\my.ini mysqlweb"

Open Windows Services and set Startup Type: Automatic, Start the service

How to configure socket connect timeout

I solved the problem by using Socket.ConnectAsync Method instead of Socket.Connect Method. After invoking the Socket.ConnectAsync(SocketAsyncEventArgs), start a timer (timer_connection), if time is up, check whether socket connection is connected (if(m_clientSocket.Connected)), if not, pop up timeout error.

private void connect(string ipAdd,string port)
    {
        try
        {
            SocketAsyncEventArgs e=new SocketAsyncEventArgs();


            m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            IPAddress ip = IPAddress.Parse(serverIp);
            int iPortNo = System.Convert.ToInt16(serverPort);
            IPEndPoint ipEnd = new IPEndPoint(ip, iPortNo);

            //m_clientSocket.
            e.RemoteEndPoint = ipEnd;
            e.UserToken = m_clientSocket;
            e.Completed+=new EventHandler<SocketAsyncEventArgs>(e_Completed);                
            m_clientSocket.ConnectAsync(e);

            if (timer_connection != null)
            {
                timer_connection.Dispose();
            }
            else
            {
                timer_connection = new Timer();
            }
            timer_connection.Interval = 2000;
            timer_connection.Tick+=new EventHandler(timer_connection_Tick);
            timer_connection.Start();
        }
        catch (SocketException se)
        {
            lb_connectStatus.Text = "Connection Failed";
            MessageBox.Show(se.Message);
        }
    }
private void e_Completed(object sender,SocketAsyncEventArgs e)
    {
        lb_connectStatus.Text = "Connection Established";
        WaitForServerData();
    }
    private void timer_connection_Tick(object sender, EventArgs e)
    {
        if (!m_clientSocket.Connected)
        {
            MessageBox.Show("Connection Timeout");
            //m_clientSocket = null;

            timer_connection.Stop();
        }
    }

Runtime vs. Compile time

here's a very simple answer:

Runtime and compile time are programming terms that refer to different stages of software program development. In order to create a program, a developer first writes source code, which defines how the program will function. Small programs may only contain a few hundred lines of source code, while large programs may contain hundreds of thousands of lines of source code. The source code must be compiled into machine code in order to become and executable program. This compilation process is referred to as compile time.(think of a compiler as a translator)

A compiled program can be opened and run by a user. When an application is running, it is called runtime.

The terms "runtime" and "compile time" are often used by programmers to refer to different types of errors. A compile time error is a problem such as a syntax error or missing file reference that prevents the program from successfully compiling. The compiler produces compile time errors and usually indicates what line of the source code is causing the problem.

If a program's source code has already been compiled into an executable program, it may still have bugs that occur while the program is running. Examples include features that don't work, unexpected program behavior, or program crashes. These types of problems are called runtime errors since they occur at runtime.

The reference

Is the Scala 2.8 collections library a case of "the longest suicide note in history"?

I think primary problem with that method is that the (implicit bf : CanBuildFrom[Repr, B, That]) goes without any explanation. Even though I know what implicit arguments are there's nothing indicating how this affects the call. Chasing through the scaladoc only leaves me more confused (few of the classes related to CanBuildFrom even have documentation).

I think a simple "there must be an implicit object in scope for bf that provides a builder for objects of type B into the return type That" would help somewhat, but it's kind of a heady concept when all you really want to do is map A's to B's. In fact, I'm not sure that's right, because I don't know what the type Repr means, and the documentation for Traversable certainly gives no clue at all.

So, I'm left with two options, neither of them pleasant:

  • Assume it will just work how the old map works and how map works in most other languages
  • Dig into the source code some more

I get that Scala is essentially exposing the guts of how these things work and that ultimately this is provide a way to do what oxbow_lakes is describing. But it's a distraction in the signature.

Make EditText ReadOnly

Please use this code..

Edittext.setEnabled(false);

How to change the font on the TextView?

It's a little old, but I improved the class CustomFontLoader a little bit and I wanted to share it so it can be helpfull. Just create a new class with this code.

 import android.content.Context;
 import android.graphics.Typeface;

public enum FontLoader {

ARIAL("arial"),
TIMES("times"),
VERDANA("verdana"),
TREBUCHET("trbuchet"),
GEORGIA("georgia"),
GENEVA("geneva"),
SANS("sans"),
COURIER("courier"),
TAHOMA("tahoma"),
LUCIDA("lucida");   


private final String name;
private Typeface typeFace;


private FontLoader(final String name) {
    this.name = name;

    typeFace=null;  
}

public static Typeface getTypeFace(Context context,String name){
    try {
        FontLoader item=FontLoader.valueOf(name.toUpperCase(Locale.getDefault()));
        if(item.typeFace==null){                
            item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");                 
        }           
        return item.typeFace;
    } catch (Exception e) {         
        return null;
    }                   
}
public static Typeface getTypeFace(Context context,int id){
    FontLoader myArray[]= FontLoader.values();
    if(!(id<myArray.length)){           
        return null;
    } 
    try {
        if(myArray[id].typeFace==null){     
            myArray[id].typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+myArray[id].name+".ttf");                       
        }       
        return myArray[id].typeFace;    
    }catch (Exception e) {          
        return null;
    }   

}

public static Typeface getTypeFaceByName(Context context,String name){      
    for(FontLoader item: FontLoader.values()){              
        if(name.equalsIgnoreCase(item.name)){
            if(item.typeFace==null){
                try{
                    item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");     
                }catch (Exception e) {          
                    return null;
                }   
            }
            return item.typeFace;
        }               
    }
    return null;
}   

public static void loadAllFonts(Context context){       
    for(FontLoader item: FontLoader.values()){              
        if(item.typeFace==null){
            try{
                item.typeFace=Typeface.createFromAsset(context.getAssets(), "fonts/"+item.name+".ttf");     
            }catch (Exception e) {
                item.typeFace=null;
            }   
        }                
    }       
}   
}

Then just use this code on you textview:

 Typeface typeFace=FontLoader.getTypeFace(context,"arial");  
 if(typeFace!=null) myTextView.setTypeface(typeFace);

val() doesn't trigger change() in jQuery

onchange only fires when the user types into the input and then the input loses focus.

You can manually call the onchange event using after setting the value:

$("#mytext").change(); // someObject.onchange(); in standard JS

Alternatively, you can trigger the event using:

$("#mytext").trigger("change");

How can I switch my git repository to a particular commit

All the above commands create a new branch and with the latest commit being the one specified in the command, but just in case you want your current branch HEAD to move to the specified commit, below is the command:

 git checkout <commit_hash>

It detaches and point the HEAD to specified commit and saves from creating a new branch when the user just wants to view the branch state till that particular commit.


You then might want to go back to the latest commit & fix the detached HEAD:

Fix a Git detached head?

Uncaught SyntaxError: Unexpected token :

I got a "SyntaxError: Unexpected token I" when I used jQuery.getJSON() to try to de-serialize a floating point value of Infinity, encoded as INF, which is illegal in JSON.

Generating a SHA-256 hash from the Linux command line

If you have installed openssl, you can use:

echo -n "foobar" | openssl dgst -sha256

For other algorithms you can replace -sha256 with -md4, -md5, -ripemd160, -sha, -sha1, -sha224, -sha384, -sha512 or -whirlpool.

What's the difference between align-content and align-items?

The align-items property of flex-box aligns the items inside a flex container along the cross axis just like justify-content does along the main axis. (For the default flex-direction: row the cross axis corresponds to vertical and the main axis corresponds to horizontal. With flex-direction: column those two are interchanged respectively).

Here's an example of how align-items:center looks:

align-items: center

But align-content is for multi line flexible boxes. It has no effect when items are in a single line. It aligns the whole structure according to its value. Here's an example for align-content: space-around;: enter image description here

And here's how align-content: space-around; with align-items:center looks: enter image description here

Note the 3rd box and all other boxes in first line change to vertically centered in that line.

Here are some codepen links to play with:

http://codepen.io/asim-coder/pen/MKQWbb

http://codepen.io/asim-coder/pen/WrMNWR

Here's a super cool pen which shows and lets you play with almost everything in flexbox.

How to remove from a map while iterating it?

The standard associative-container erase idiom:

for (auto it = m.cbegin(); it != m.cend() /* not hoisted */; /* no increment */)
{
  if (must_delete)
  {
    m.erase(it++);    // or "it = m.erase(it)" since C++11
  }
  else
  {
    ++it;
  }
}

Note that we really want an ordinary for loop here, since we are modifying the container itself. The range-based loop should be strictly reserved for situations where we only care about the elements. The syntax for the RBFL makes this clear by not even exposing the container inside the loop body.

Edit. Pre-C++11, you could not erase const-iterators. There you would have to say:

for (std::map<K,V>::iterator it = m.begin(); it != m.end(); ) { /* ... */ }

Erasing an element from a container is not at odds with constness of the element. By analogy, it has always been perfectly legitimate to delete p where p is a pointer-to-constant. Constness does not constrain lifetime; const values in C++ can still stop existing.

Passing ArrayList through Intent

Suppose you need to pass an arraylist of following class from current activity to next activity // class of the objects those in the arraylist // remember to implement the class from Serializable interface // Serializable means it converts the object into stream of bytes and helps to transfer that object

public class Question implements Serializable {
... 
... 
...
}

in your current activity you probably have an ArrayList as follows

ArrayList<Question> qsList = new ArrayList<>();
qsList.add(new Question(1));
qsList.add(new Question(2));
qsList.add(new Question(3));

// intialize Bundle instance
Bundle b = new Bundle();
// putting questions list into the bundle .. as key value pair.
// so you can retrieve the arrayList with this key
b.putSerializable("questions", (Serializable) qsList);
Intent i = new Intent(CurrentActivity.this, NextActivity.class);
i.putExtras(b);
startActivity(i);

in order to get the arraylist within the next activity

//get the bundle
Bundle b = getIntent().getExtras();
//getting the arraylist from the key
ArrayList<Question> q = (ArrayList<Question>) b.getSerializable("questions");

Accessing Google Spreadsheets with C# using Google Data API

The most upvoted answer from @Kelly is no longer valid as @wescpy says. However after 2020-03-03 it will not work at all since the library used uses Google Sheets v3 API.

The Google Sheets v3 API will be shut down on March 3, 2020

https://developers.google.com/sheets/api/v3

This was announced 2019-09-10 by Google:

https://cloud.google.com/blog/products/g-suite/migrate-your-apps-use-latest-sheets-api

New code sample for Google Sheets v4 API:

Go to

https://developers.google.com/sheets/api/quickstart/dotnet

and generate credentials.json. Then install Google.Apis.Sheets.v4 NuGet and try the following sample:

Note that I got the error Unable to parse range: Class Data!A2:E with the example code but with my spreadsheet. Changing to Sheet1!A2:E worked however since my sheet was named that. Also worked with only A2:E.

using Google.Apis.Auth.OAuth2;
using Google.Apis.Sheets.v4;
using Google.Apis.Sheets.v4.Data;
using Google.Apis.Services;
using Google.Apis.Util.Store;
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;

namespace SheetsQuickstart
{
    class Program
    {
        // If modifying these scopes, delete your previously saved credentials
        // at ~/.credentials/sheets.googleapis.com-dotnet-quickstart.json
        static string[] Scopes = { SheetsService.Scope.SpreadsheetsReadonly };
        static string ApplicationName = "Google Sheets API .NET Quickstart";

        static void Main(string[] args)
        {
            UserCredential credential;

            using (var stream =
                new FileStream("credentials.json", FileMode.Open, FileAccess.Read))
            {
                // The file token.json stores the user's access and refresh tokens, and is created
                // automatically when the authorization flow completes for the first time.
                string credPath = "token.json";
                credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    Scopes,
                    "user",
                    CancellationToken.None,
                    new FileDataStore(credPath, true)).Result;
                Console.WriteLine("Credential file saved to: " + credPath);
            }

            // Create Google Sheets API service.
            var service = new SheetsService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credential,
                ApplicationName = ApplicationName,
            });

            // Define request parameters.
            String spreadsheetId = "1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms";
            String range = "Class Data!A2:E";
            SpreadsheetsResource.ValuesResource.GetRequest request =
                    service.Spreadsheets.Values.Get(spreadsheetId, range);

            // Prints the names and majors of students in a sample spreadsheet:
            // https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit
            ValueRange response = request.Execute();
            IList<IList<Object>> values = response.Values;
            if (values != null && values.Count > 0)
            {
                Console.WriteLine("Name, Major");
                foreach (var row in values)
                {
                    // Print columns A and E, which correspond to indices 0 and 4.
                    Console.WriteLine("{0}, {1}", row[0], row[4]);
                }
            }
            else
            {
                Console.WriteLine("No data found.");
            }
            Console.Read();
        }
    }
}

Convert list of ASCII codes to string (byte array) in Python

I much prefer the array module to the struct module for this kind of tasks (ones involving sequences of homogeneous values):

>>> import array
>>> array.array('B', [17, 24, 121, 1, 12, 222, 34, 76]).tostring()
'\x11\x18y\x01\x0c\xde"L'

no len call, no string manipulation needed, etc -- fast, simple, direct, why prefer any other approach?!

printf %f with only 2 numbers after the decimal point?

I suggest to learn it with printf because for many cases this will be sufficient for your needs and you won't need to create other objects.

double d = 3.14159;     
printf ("%.2f", d);

But if you need rounding please refer to this post

https://stackoverflow.com/a/153785/2815227

How to install crontab on Centos

As seen in Install crontab on CentOS, the crontab package in CentOS is vixie-cron. Hence, do install it with:

yum install vixie-cron

And then start it with:

service crond start

To make it persistent, so that it starts on boot, use:

chkconfig crond on

On CentOS 7 you need to use cronie:

yum install cronie

On CentOS 6 you can install vixie-cron, but the real package is cronie:

yum install vixie-cron

and

yum install cronie

In both cases you get the same output:

.../...
==================================================================
 Package         Arch       Version         Repository      Size
==================================================================
Installing:
 cronie          x86_64     1.4.4-12.el6    base             73 k
Installing for dependencies:
 cronie-anacron  x86_64     1.4.4-12.el6    base             30 k
 crontabs        noarch     1.10-33.el6     base             10 k
 exim            x86_64     4.72-6.el6      epel            1.2 M

Transaction Summary
==================================================================
Install       4 Package(s)

Java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException

I also have the same error. I have updated the jackson library version and error has gone.

<!-- Jackson to convert Java object to Json -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.4</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.4</version>
        </dependency>
    </dependencies>

and also check your data classes that have you created getters and setters for all the properties.

How to change the remote repository for a git submodule?

With Git 2.25 (Q1 2020), you can modify it.
See "Git submodule url changed" and the new command

git submodule set-url [--] <path> <newurl>

Original answer (May 2009, ten years ago)

Actually, a patch has been submitted in April 2009 to clarify gitmodule role.

So now the gitmodule documentation does not yet include:

The .gitmodules file, located in the top-level directory of a git working tree, is a text file with a syntax matching the requirements -of linkgit:git-config1.
[NEW]:
As this file is managed by Git, it tracks the +records of a project's submodules.
Information stored in this file is used as a hint to prime the authoritative version of the record stored in the project configuration file.
User specific record changes (e.g. to account for differences in submodule URLs due to networking situations) should be made to the configuration file, while record changes to be propagated (e.g. +due to a relocation of the submodule source) should be made to this file.

That pretty much confirm Jim's answer.


If you follow this git submodule tutorial, you see you need a "git submodule init" to add the submodule repository URLs to .git/config.

"git submodule sync" has been added in August 2008 precisely to make that task easier when URL changes (especially if the number of submodules is important).
The associate script with that command is straightforward enough:

module_list "$@" |
while read mode sha1 stage path
do
    name=$(module_name "$path")
    url=$(git config -f .gitmodules --get submodule."$name".url)
    if test -e "$path"/.git
    then
    (
        unset GIT_DIR
        cd "$path"
        remote=$(get_default_remote)
        say "Synchronizing submodule url for '$name'"
        git config remote."$remote".url "$url"
    )
    fi
done

The goal remains: git config remote."$remote".url "$url"

Overlapping elements in CSS

Use CSS grid and set all the grid items to be in the same cell.

.layered {
  display: grid;
}

.layered > * {
  grid-column-start: 1;
  grid-row-start: 1;
}

Adding the layered class to an element causes all it's children to be layered on top of each other.

if the layers are not the same size you can set the justify-items and align-items properties to set the horizontal and vertical alignment respectively.


Demo:

JsFiddle

_x000D_
_x000D_
.layered {
  display: grid;

  /* Set horizontal alignment of items in, case they have a different width. */
  /* justify-items: start | end | center | stretch (default); */
  justify-items: start;

  /* Set vertical alignment of items, in case they have a different height. */
  /* align-items: start | end | center | stretch (default); */
  align-items: start;
}

.layered > * {
  grid-column-start: 1;
  grid-row-start: 1;
}


/* for demonstration purposes only */
.layered > * {
  outline: 1px solid red;
  background-color: rgba(255, 255, 255, 0.4)
}
_x000D_
<div class="layered">
  <img src="https://via.placeholder.com/250x100?text=first" />
  <p>
    2
  </p>
  <div>
    <p>
      Third layer
    </p>
    <p>
      Third layer continued
    </p>
    <p>
      Third layer continued
    </p>
    <p>
      Third layer continued
    </p>
  </div>
</div>
_x000D_
_x000D_
_x000D_

How to find integer array size in java

we can find length of array by using array_name.length attribute

int [] i = i.length;

Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)

The right mental model for using mutexes: The mutex protects an invariant.

Why are you sure that this is really right mental model for using mutexes? I think right model is protecting data but not invariants.

The problem of protecting invariants presents even in single-threaded applications and has nothing common with multi-threading and mutexes.

Furthermore, if you need to protect invariants, you still may use binary semaphore wich is never recursive.

CSS3 gradient background set on body doesn't stretch but instead repeats?

instead of 100% i just add some pixxel got this now and it works for whole page without gap:

html {     
height: 1420px; } 
body {     
height: 1400px;     
margin: 0;     
background-repeat: no-repeat; }

C# HttpClient 4.5 multipart/form-data upload

my result looks like this:

public static async Task<string> Upload(byte[] image)
{
     using (var client = new HttpClient())
     {
         using (var content =
             new MultipartFormDataContent("Upload----" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
         {
             content.Add(new StreamContent(new MemoryStream(image)), "bilddatei", "upload.jpg");

              using (
                 var message =
                     await client.PostAsync("http://www.directupload.net/index.php?mode=upload", content))
              {
                  var input = await message.Content.ReadAsStringAsync();

                  return !string.IsNullOrWhiteSpace(input) ? Regex.Match(input, @"http://\w*\.directupload\.net/images/\d*/\w*\.[a-z]{3}").Value : null;
              }
          }
     }
}

How To Make Circle Custom Progress Bar in Android

I've encountered same problem and not found any appropriate solution for my case, so I decided to go another way. I've created custom drawable class. Within this class I've created 2 Paints for progress line and background line (with some bigger stroke). First of all set startAngle and sweepAngle in constructor:

    mSweepAngle = 0;
    mStartAngle = 270;

Here is onDraw method of this class:

@Override
public void draw(Canvas canvas) {
    // draw background line
    canvas.drawArc(mRectF, 0, 360, false, mPaintBackground);
    // draw progress line
    canvas.drawArc(mRectF, mStartAngle, mSweepAngle, false, mPaintProgress);
}

So now all you need to do is set this drawable as a backgorund of the view, in background thread change sweepAngle:

mSweepAngle += 360 / totalTimerTime // this is mStep

and directly call InvalidateSelf() with some interval (e.g every 1 second or more often if you want smooth progress changes) on the view that have this drawable as a background. Thats it!

P.S. I know, I know...of course you want some more code. So here it is all flow:

  1. Create XML view :

     <View
     android:id="@+id/timer"
     android:layout_width="match_parent"
     android:layout_height="match_parent"/>
    
  2. Create and configure Custom Drawable class (as I described above). Don't forget to setup Paints for lines. Here paint for progress line:

    mPaintProgress = new Paint();
    mPaintProgress.setAntiAlias(true);
    mPaintProgress.setStyle(Paint.Style.STROKE);
    mPaintProgress.setStrokeWidth(widthProgress);
    mPaintProgress.setStrokeCap(Paint.Cap.ROUND);
    mPaintProgress.setColor(colorThatYouWant);
    

Same for backgroung paint (set width little more if you want)

  1. In drawable class create method for updating (Step calculation described above)

    public void update() {
        mSweepAngle += mStep;
        invalidateSelf();
    }
    
  2. Set this drawable class to YourTimerView (I did it in runtime) - view with @+id/timer from xml above:

    OurSuperDrawableClass superDrawable = new OurSuperDrawableClass(); YourTimerView.setBackgroundDrawable(superDrawable);

  3. Create background thread with runnable and update view:

    YourTimerView.post(new Runnable() {
        @Override
        public void run() {
            // update progress view
            superDrawable.update();
        }
    });
    

Thats it ! Enjoy your cool progress bar. Here screenshot of result if you're too bored of this amount of text.enter image description here

no module named urllib.parse (How should I install it?)

pip install -U websocket 

I just use this to fix my problem

Hide text within HTML?

You said that you can’t use HTML comments because the CMS filters them out. So I assume that you really want to hide this content and you don’t need to display it ever.

In that case, you shouldn’t use CSS (only), as you’d only play on the presentation level, not affecting the content level. Your content should also be hidden for user-agents ignoring the CSS (people using text browsers, feed readers, screen readers; bots; etc.).

In HTML5 there is the global hidden attribute:

When specified on an element, it indicates that the element is not yet, or is no longer, directly relevant to the page's current state, or that it is being used to declare content to be reused by other parts of the page as opposed to being directly accessed by the user. User agents should not render elements that have the hidden attribute specified.

Example (using the small element here, because it’s an "attribution"):

<small hidden>Thanks to John Doe for this idea.</small>

As a fallback (for user-agents that don’t know the hidden attribute), you can specify in your CSS:

[hidden] {display:none;}

An general element for plain text could be the script element used as "data block":

<script type="text/plain" hidden>
Thanks to John Doe for this idea.
</script>

Alternatively, you could also use data-* attributes on existing elements (resp. on new div elements if you want to group some elements for the attribution):

<p data-attribution="Thanks to John Doe for this idea!">This is some visible example content …</p>

html select option SELECTED

You're missing quotes for $_GET['sel'] - fixing this might help solving your issue sooner :)

Passing an array using an HTML form hidden element

You can do it like this:

<input type="hidden" name="result" value="<?php foreach($postvalue as $value) echo $postvalue.","; ?>">

How to retrieve the LoaderException property?

Another Alternative for those who are probing around and/or in interactive mode:

$Error[0].Exception.LoaderExceptions

Note: [0] grabs the most recent Error from the stack

Do copyright dates need to be updated?

It is important to recognize that the copyright laws have changed and that for non-US sources, especially after the USA joining the Berne Convention on March 1, 1989, copyright registration in not necessary for enforcement of a copyright notice.
Here is a resumé quoted from the Cornell University Law School (copied on March 4, 2015 from https://www.law.cornell.edu/wex/copyright:

"Copyright copyright: an overview

The U.S. Copyright Act, 17 U.S.C. §§ 101 - 810, is Federal legislation enacted by Congress under its Constitutional grant of authority to protect the writings of authors. See U.S. Constitution, Article I, Section 8. Changing technology has led to an ever expanding understanding of the word "writings." The Copyright Act now reaches architectural design, software, the graphic arts, motion pictures, and sound recordings. See § 106. As of January 1, 1978, all works of authorship fixed in a tangible medium of expression and within the subject matter of copyright were deemed to fall within the exclusive jurisdiction of the Copyright Act regardless of whether the work was created before or after that date and whether published or unpublished. See § 301. See also preemption.

The owner of a copyright has the exclusive right to reproduce, distribute, perform, display, license, and to prepare derivative works based on the copyrighted work. See § 106. The exclusive rights of the copyright owner are subject to limitation by the doctrine of "fair use." See § 107. Fair use of a copyrighted work for purposes such as criticism, comment, news reporting, teaching, scholarship, or research is not copyright infringement. To determine whether or not a particular use qualifies as fair use, courts apply a multi-factor balancing test. See § 107.

Copyright protection subsists in original works of authorship fixed in any tangible medium of expression from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device. See § 102. Copyright protection does not extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery. For example, if a book is written describing a new system of bookkeeping, copyright protection only extends to the author's description of the bookkeeping system; it does not protect the system itself. See Baker v. Selden, 101 U.S. 99 (1879).

According to the Copyright Act of 1976, registration of copyright is voluntary and may take place at any time during the term of protection. See § 408. Although registration of a work with the Copyright Office is not a precondition for protection, an action for copyright infringement may not be commenced until the copyright has been formally registered with the Copyright Office. See § 411.

Deposit of copies with the Copyright Office for use by the Library of Congress is a separate requirement from registration. Failure to comply with the deposit requirement within three months of publication of the protected work may result in a civil fine. See § 407. The Register of Copyrights may exempt certain categories of material from the deposit requirement.

In 1989 the U.S. joined the Berne Convention for the Protection of Literary and Artistic Works. In accordance with the requirements of the Berne Convention, notice is no longer a condition of protection for works published after March 1, 1989. This change to the notice requirement applies only prospectively to copies of works publicly distributed after March 1, 1989.

The Berne Convention also modified the rule making copyright registration a precondition to commencing a lawsuit for infringement. For works originating from a Berne Convention country, an infringement action may be initiated without registering the work with the U.S. Copyright Office. However, for works of U.S. origin, registration prior to filing suit is still required.

The federal agency charged with administering the act is the Copyright Office of the Library of Congress. See § 701 of the act. Its regulations are found in Parts 201 - 204 of title 37 of the Code of Federal Regulations."

How can I create objects while adding them into a vector?

Question 1:

   vectorOfGamers.push_back(Player)

This is problematic because you cannot directly push a class name into a vector. You can either push an object of class into the vector or push reference or pointer to class type into the vector. For example:

vectorOfGamers.push_back(Player(name, id)) 
  //^^assuming name and id are parameters to the vector, call Player constructor
  //^^In other words, push `instance`  of Player class into vector

Question 2:

These 3 classes derives from Gamer. Can I create vector to hold objects of Dealer, Bot and Player at the same time? How do I do that?

Yes you can. You can create a vector of pointers that points to the base class Gamer. A good choice is to use a vector of smart_pointer, therefore, you do not need to manage pointer memory by yourself. Since the other three classes are derived from Gamer, based on polymorphism, you can assign derived class objects to base class pointers. You may find more information from this post: std::vector of objects / pointers / smart pointers to pass objects (buss error: 10)?

sql - insert into multiple tables in one query

Multiple SQL statements must be executed with the mysqli_multi_query() function.

Example (MySQLi Object-oriented):

    <?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

$sql = "INSERT INTO names (firstname, lastname)
VALUES ('inpute value here', 'inpute value here');";
$sql .= "INSERT INTO phones (landphone, mobile)
VALUES ('inpute value here', 'inpute value here');";

if ($conn->multi_query($sql) === TRUE) {
    echo "New records created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

Trying to mock datetime.date.today(), but not working

You can mock datetime using this:

In the module sources.py:

import datetime


class ShowTime:
    def current_date():
        return datetime.date.today().strftime('%Y-%m-%d')

In your tests.py:

from unittest import TestCase, mock
import datetime


class TestShowTime(TestCase):
    def setUp(self) -> None:
        self.st = sources.ShowTime()
        super().setUp()

    @mock.patch('sources.datetime.date')
    def test_current_date(self, date_mock):
        date_mock.today.return_value = datetime.datetime(year=2019, month=10, day=1)
        current_date = self.st.current_date()
        self.assertEqual(current_date, '2019-10-01')

how to use JSON.stringify and json_decode() properly

stripslashes(htmlspecialchars(JSON_DATA))

python: sys is not defined

In addition to the answers given above, check the last line of the error message in your console. In my case, the 'site-packages' path in sys.path.append('.....') was wrong.

How to find and turn on USB debugging mode on Nexus 4

Looking for About Phone in Settings. And scroll down till you see Build number. Tap here till you see Toast message tell you have just enable developer mode.

Back to settings, you can see options: "Developer options"

Set up adb on Mac OS X

If you are using zsh terminal do the following:

1) Open .zprofile file with the editor of your choice like "open -a xcode ~/.zprofile"

2) Add new PATH or Env Variable in .zprofile Save the file and quit the editor.

3) Execute your .zprofile to update your PATH: source ~/.zprofile

What's the purpose of git-mv?

git mv moves the file, updating the index to record the replaced file path, as well as updating any affected git submodules. Unlike a manual move, it also detects case-only renames that would not otherwise be detected as a change by git.

It is similar (though not identical) in behavior to moving the file externally to git, removing the old path from the index using git rm, and adding the new one to the index using git add.

Answer Motivation

This question has a lot of great partial answers. This answer is an attempt to combine them into a single cohesive answer. Additionally, one thing not called out by any of the other answers is the fact that the man page actually does mostly answer the question, but it's perhaps less obvious than it could be.

Detailed Explanation

Three different effects are called out in the man page:

  1. The file, directory, or symlink is moved in the filesystem:

    git-mv - Move or rename a file, a directory, or a symlink

  2. The index is updated, adding the new path and removing the previous one:

    The index is updated after successful completion, but the change must still be committed.

  3. Moved submodules are updated to work at the new location:

    Moving a submodule using a gitfile (which means they were cloned with a Git version 1.7.8 or newer) will update the gitfile and core.worktree setting to make the submodule work in the new location. It also will attempt to update the submodule.<name>.path setting in the gitmodules(5) file and stage that file (unless -n is used).

As mentioned in this answer, git mv is very similar to moving the file, adding the new path to the index, and removing the previous path from the index:

mv oldname newname
git add newname
git rm oldname

However, as this answer points out, git mv is not strictly identical to this in behavior. Moving the file via git mv adds the new path to the index, but not any modified content in the file. Using the three individual commands, on the other hand, adds the entire file to the index, including any modified content. This could be relevant when using a workflow which patches the index, rather than adding all changes in the file.

Additionally, as mentioned in this answer and this comment, git mv has the added benefit of handling case-only renames on file systems that are case-insensitive but case-preserving, as is often the case in current macOS and Windows file systems. For example, in such systems, git would not detect that the file name has changed after moving a file via mv Mytest.txt MyTest.txt, whereas using git mv Mytest.txt MyTest.txt would successfully update its name.

Array to String PHP?

You can use the PHP string function implode()

Like,

<?php
  $sports=$_POST['sports'];;
  $festival=$_POST['festival'];
  $food=$_POST['food'];
  $array=[$sports,$festival,$food];
  $string=implode('|',$array);
  echo $string;
?>

If, for example, $sports='football'; $festival='janmastami'; $food='biriyani';

Then output would be:

football|janmastami|biriyani

For more details on PHP implode() function refer to w3schools

Should I use typescript? or I can just use ES6?

I've been using Typescript in my current angular project for about a year and a half and while there are a few issues with definitions every now and then the DefinitelyTyped project does an amazing job at keeping up with the latest versions of most popular libraries.

Having said that there is a definite learning curve when transitioning from vanilla JavaScript to TS and you should take into account the ability of you and your team to make that transition. Also if you are going to be using angular 1.x most of the examples you will find online will require you to translate them from JS to TS and overall there are not a lot of resources on using TS and angular 1.x together right now.

If you plan on using angular 2 there are a lot of examples using TS and I think the team will continue to provide most of the documentation in TS, but you certainly don't have to use TS to use angular 2.

ES6 does have some nice features and I personally plan on getting more familiar with it but I would not consider it a production-ready language at this point. Mainly due to a lack of support by current browsers. Of course, you can write your code in ES6 and use a transpiler to get it to ES5, which seems to be the popular thing to do right now.

Overall I think the answer would come down to what you and your team are comfortable learning. I personally think both TS and ES6 will have good support and long futures, I prefer TS though because you tend to get language features quicker and right now the tooling support (in my opinion) is a little better.

Text was truncated or one or more characters had no match in the target code page including the primary key in an unpivot

SQL Server may be able to suggest the right data type for you (even when it does not choose the right type by default) - clicking the "Suggest Types" button (shown in your screenshot above) allows you to have SQL Server scan the source and suggest a data type for the field that's throwing an error. In my case, choosing to scan 20000 rows to generate the suggestions, and using the resulting suggested data type, fixed the issue.

How do I compile a .cpp file on Linux?

You'll need to compile it using:

g++ inputfile.cpp -o outputbinary

The file you are referring has a missing #include <cstdlib> directive, if you also include that in your file, everything shall compile fine.

How can I convert string to double in C++?

atof and strtod do what you want but are very forgiving. If you don't want to accept strings like "32asd" as valid you need to wrap strtod in a function such as this:

#include <stdlib.h>
double strict_str2double(char* str)
{
    char* endptr;
    double value = strtod(str, &endptr);
    if (*endptr) return 0;
    return value;
}

How do I run a command on an already existing Docker container?

I am running windows container and I need to look inside the docker container for files and folder created and copied.

In order to do that I used following docker entrypoint command to get the command prompt running inside the container or attach to the container.

ENTRYPOINT ["C:\\Windows\\System32\\cmd.exe", "-D", "FOREGROUND"]

That helped me both to the command prompt attach to container and to keep the container a live. :)

Check if a string matches a regex in Bash script

I would use expr match instead of =~:

expr match "$date" "[0-9]\{8\}" >/dev/null && echo yes

This is better than the currently accepted answer of using =~ because =~ will also match empty strings, which IMHO it shouldn't. Suppose badvar is not defined, then [[ "1234" =~ "$badvar" ]]; echo $? gives (incorrectly) 0, while expr match "1234" "$badvar" >/dev/null ; echo $? gives correct result 1.

We have to use >/dev/null to hide expr match's output value, which is the number of characters matched or 0 if no match found. Note its output value is different from its exit status. The exit status is 0 if there's a match found, or 1 otherwise.

Generally, the syntax for expr is:

expr match "$string" "$lead"

Or:

expr "$string" : "$lead"

where $lead is a regular expression. Its exit status will be true (0) if lead matches the leading slice of string (Is there a name for this?). For example expr match "abcdefghi" "abc"exits true, but expr match "abcdefghi" "bcd" exits false. (Credit to @Carlo Wood for pointing out this.

Best way to require all files from a directory in ruby?

I'm a few years late to the party, but I kind of like this one-line solution I used to get rails to include everything in app/workers/concerns:

Dir[ Rails.root.join *%w(app workers concerns *) ].each{ |f| require f }

Calling Oracle stored procedure from C#?

Instead of

cmd = new OracleCommand("ProcName", con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";

You can also use this syntax:

cmd = new OracleCommand("BEGIN ProcName(:p0); END;", con);
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";

Note, if you set cmd.BindByName = False (which is the default) then you have to add the parameters in the same order as they are written in your command string, the actual names are not relevant. For cmd.BindByName = True the parameter names have to match, the order does not matter.

In case of a function call the command string would be like this:

cmd = new OracleCommand("BEGIN :ret := ProcName(:ParName); END;", con);
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add("ret", OracleDbType.RefCursor, ParameterDirection.ReturnValue);    
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";
// cmd.ExecuteNonQuery(); is not needed, otherwise the function is executed twice!
var da = new OracleDataAdapter(cmd);
da.Fill(dt);

In Oracle, is it possible to INSERT or UPDATE a record through a view?

Views in Oracle may be updateable under specific conditions. It can be tricky, and usually is not advisable.

From the Oracle 10g SQL Reference:

Notes on Updatable Views

An updatable view is one you can use to insert, update, or delete base table rows. You can create a view to be inherently updatable, or you can create an INSTEAD OF trigger on any view to make it updatable.

To learn whether and in what ways the columns of an inherently updatable view can be modified, query the USER_UPDATABLE_COLUMNS data dictionary view. The information displayed by this view is meaningful only for inherently updatable views. For a view to be inherently updatable, the following conditions must be met:

  • Each column in the view must map to a column of a single table. For example, if a view column maps to the output of a TABLE clause (an unnested collection), then the view is not inherently updatable.
  • The view must not contain any of the following constructs:
    • A set operator
    • a DISTINCT operator
    • An aggregate or analytic function
    • A GROUP BY, ORDER BY, MODEL, CONNECT BY, or START WITH clause
    • A collection expression in a SELECT list
    • A subquery in a SELECT list
    • A subquery designated WITH READ ONLY
    • Joins, with some exceptions, as documented in Oracle Database Administrator's Guide

In addition, if an inherently updatable view contains pseudocolumns or expressions, then you cannot update base table rows with an UPDATE statement that refers to any of these pseudocolumns or expressions.

If you want a join view to be updatable, then all of the following conditions must be true:

  • The DML statement must affect only one table underlying the join.
  • For an INSERT statement, the view must not be created WITH CHECK OPTION, and all columns into which values are inserted must come from a key-preserved table. A key-preserved table is one for which every primary key or unique key value in the base table is also unique in the join view.
  • For an UPDATE statement, all columns updated must be extracted from a key-preserved table. If the view was created WITH CHECK OPTION, then join columns and columns taken from tables that are referenced more than once in the view must be shielded from UPDATE.
  • For a DELETE statement, if the join results in more than one key-preserved table, then Oracle Database deletes from the first table named in the FROM clause, whether or not the view was created WITH CHECK OPTION.

Spark difference between reduceByKey vs groupByKey vs aggregateByKey vs combineByKey

groupByKey:

Syntax:

sparkContext.textFile("hdfs://")
                    .flatMap(line => line.split(" ") )
                    .map(word => (word,1))
                    .groupByKey()
                    .map((x,y) => (x,sum(y)))

groupByKey can cause out of disk problems as data is sent over the network and collected on the reduce workers.

reduceByKey:

Syntax:

sparkContext.textFile("hdfs://")
                    .flatMap(line => line.split(" "))
                    .map(word => (word,1))
                    .reduceByKey((x,y)=> (x+y))

Data are combined at each partition, only one output for one key at each partition to send over the network. reduceByKey required combining all your values into another value with the exact same type.

aggregateByKey:

same as reduceByKey, which takes an initial value.

3 parameters as input i. initial value ii. Combiner logic iii. sequence op logic

Example:

val keysWithValuesList = Array("foo=A", "foo=A", "foo=A", "foo=A", "foo=B", "bar=C", "bar=D", "bar=D")
    val data = sc.parallelize(keysWithValuesList)
    //Create key value pairs
    val kv = data.map(_.split("=")).map(v => (v(0), v(1))).cache()
    val initialCount = 0;
    val addToCounts = (n: Int, v: String) => n + 1
    val sumPartitionCounts = (p1: Int, p2: Int) => p1 + p2
    val countByKey = kv.aggregateByKey(initialCount)(addToCounts, sumPartitionCounts)

ouput: Aggregate By Key sum Results bar -> 3 foo -> 5

combineByKey:

3 parameters as input

  1. Initial value: unlike aggregateByKey, need not pass constant always, we can pass a function that will return a new value.
  2. merging function
  3. combine function

Example:

val result = rdd.combineByKey(
                        (v) => (v,1),
                        ( (acc:(Int,Int),v) => acc._1 +v , acc._2 +1 ) ,
                        ( acc1:(Int,Int),acc2:(Int,Int) => (acc1._1+acc2._1) , (acc1._2+acc2._2)) 
                        ).map( { case (k,v) => (k,v._1/v._2.toDouble) })
        result.collect.foreach(println)

reduceByKey,aggregateByKey,combineByKey preferred over groupByKey

Reference: Avoid groupByKey

Setting an environment variable before a command in Bash is not working for the second command in a pipe

You can also use eval:

FOO=bar eval 'somecommand someargs | somecommand2'

Since this answer with eval doesn't seem to please everyone, let me clarify something: when used as written, with the single quotes, it is perfectly safe. It is good as it will not launch an external process (like the accepted answer) nor will it execute the commands in an extra subshell (like the other answer).

As we get a few regular views, it's probably good to give an alternative to eval that will please everyone, and has all the benefits (and perhaps even more!) of this quick eval “trick”. Just use a function! Define a function with all your commands:

mypipe() {
    somecommand someargs | somecommand2
}

and execute it with your environment variables like this:

FOO=bar mypipe

How do I redirect in expressjs while passing some context?

There are a few ways of passing data around to different routes. The most correct answer is, of course, query strings. You'll need to ensure that the values are properly encodeURIComponent and decodeURIComponent.

app.get('/category', function(req, res) {
  var string = encodeURIComponent('something that would break');
  res.redirect('/?valid=' + string);
});

You can snag that in your other route by getting the parameters sent by using req.query.

app.get('/', function(req, res) {
  var passedVariable = req.query.valid;
  // Do something with variable
});

For more dynamic way you can use the url core module to generate the query string for you:

const url = require('url');    
app.get('/category', function(req, res) {
    res.redirect(url.format({
       pathname:"/",
       query: {
          "a": 1,
          "b": 2,
          "valid":"your string here"
        }
     }));
 });

So if you want to redirect all req query string variables you can simply do

res.redirect(url.format({
       pathname:"/",
       query:req.query,
     });
 });

And if you are using Node >= 7.x you can also use the querystring core module

const querystring = require('querystring');    
app.get('/category', function(req, res) {
      const query = querystring.stringify({
          "a": 1,
          "b": 2,
          "valid":"your string here"
      });
      res.redirect('/?' + query);
 });

Another way of doing it is by setting something up in the session. You can read how to set it up here, but to set and access variables is something like this:

app.get('/category', function(req, res) {
  req.session.valid = true;
  res.redirect('/');
});

And later on after the redirect...

app.get('/', function(req, res) {
  var passedVariable = req.session.valid;
  req.session.valid = null; // resets session variable
  // Do something
});

There is also the option of using an old feature of Express, req.flash. Doing so in newer versions of Express will require you to use another library. Essentially it allows you to set up variables that will show up and reset the next time you go to a page. It's handy for showing errors to users, but again it's been removed by default. EDIT: Found a library that adds this functionality.

Hopefully that will give you a general idea how to pass information around in an Express application.

CSS content property: is it possible to insert HTML instead of Text?

As almost noted in comments to @BoltClock's answer, in modern browsers, you can actually add some html markup to pseudo-elements using the (url()) in combination with svg's <foreignObject> element.

You can either specify an URL pointing to an actual svg file, or create it with a dataURI version (data:image/svg+xml; charset=utf8, + encodeURIComponent(yourSvgMarkup))

But note that it is mostly a hack and that there are a lot of limitations :

  • You can not load any external resources from this markup (no CSS, no images, no media etc.).
  • You can not execute script.
  • Since this won't be part of the DOM, the only way to alter it, is to pass the markup as a dataURI, and edit this dataURI in document.styleSheets. for this part, DOMParser and XMLSerializer may help.
  • While the same operation allows us to load url-encoded media in <img> tags, this won't work in pseudo-elements (at least as of today, I don't know if it is specified anywhere that it shouldn't, so it may be a not-yet implemented feature).

Now, a small demo of some html markup in a pseudo element :

_x000D_
_x000D_
/* _x000D_
**  original svg code :_x000D_
*_x000D_
*<svg width="200" height="60"_x000D_
*     xmlns="http://www.w3.org/2000/svg">_x000D_
*_x000D_
* <foreignObject width="100%" height="100%" x="0" y="0">_x000D_
* <div xmlns="http://www.w3.org/1999/xhtml" style="color: blue">_x000D_
*  I am <pre>HTML</pre>_x000D_
* </div>_x000D_
* </foreignObject>_x000D_
*</svg>_x000D_
*_x000D_
*/
_x000D_
#log::after {_x000D_
  content: url('data:image/svg+xml;%20charset=utf8,%20%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20height%3D%2260%22%20width%3D%22200%22%3E%0A%0A%20%20%3CforeignObject%20y%3D%220%22%20x%3D%220%22%20height%3D%22100%25%22%20width%3D%22100%25%22%3E%0A%09%3Cdiv%20style%3D%22color%3A%20blue%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1999%2Fxhtml%22%3E%0A%09%09I%20am%20%3Cpre%3EHTML%3C%2Fpre%3E%0A%09%3C%2Fdiv%3E%0A%20%20%3C%2FforeignObject%3E%0A%3C%2Fsvg%3E');_x000D_
}
_x000D_
<p id="log">hi</p>
_x000D_
_x000D_
_x000D_

How to correctly use the extern keyword in C

A very good article that I came about the extern keyword, along with the examples: http://www.geeksforgeeks.org/understanding-extern-keyword-in-c/

Though I do not agree that using extern in function declarations is redundant. This is supposed to be a compiler setting. So I recommend using the extern in the function declarations when it is needed.

Can linux cat command be used for writing text to file?

cat can also be used following a | to write to a file, i.e. pipe feeds cat a stream of data

Error inflating class android.support.v7.widget.Toolbar?

To fix this problem . first you must add latestandroid-support-v7-appcompat from the \sdk\extras\android\support

  1. Close the main project.
  2. Remove the android-support-v7-appcompat .
  3. Restart the Eclipse.
  4. Add the android-support-v7-appcompat .
  5. Clean,To build the project.
  6. Then open the main project and build all the projects.
  7. The error still remains. Restart eclipse. That's it.

That works for me and I will strongly recommend you to use Android Studio.

How to sort an ArrayList in Java

Implement Comparable interface to Fruit.

public class Fruit implements Comparable<Fruit> {

It implements the method

@Override
    public int compareTo(Fruit fruit) {
        //write code here for compare name
    }

Then do call sort method

Collections.sort(fruitList);

Numpy `ValueError: operands could not be broadcast together with shape ...`

If X and beta do not have the same shape as the second term in the rhs of your last line (i.e. nsample), then you will get this type of error. To add an array to a tuple of arrays, they all must be the same shape.

I would recommend looking at the numpy broadcasting rules.

Table columns, setting both min and max width with css

Tables work differently; sometimes counter-intuitively.

The solution is to use width on the table cells instead of max-width.

Although it may sound like in that case the cells won't shrink below the given width, they will actually.
with no restrictions on c, if you give the table a width of 70px, the widths of a, b and c will come out as 16, 42 and 12 pixels, respectively.
With a table width of 400 pixels, they behave like you say you expect in your grid above.
Only when you try to give the table too small a size (smaller than a.min+b.min+the content of C) will it fail: then the table itself will be wider than specified.

I made a snippet based on your fiddle, in which I removed all the borders and paddings and border-spacing, so you can measure the widths more accurately.

_x000D_
_x000D_
table {_x000D_
  width: 70px;_x000D_
}_x000D_
_x000D_
table, tbody, tr, td {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
  border: 0;_x000D_
  border-spacing: 0;_x000D_
}_x000D_
_x000D_
.a, .c {_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  background-color: #F77;_x000D_
}_x000D_
_x000D_
.a {_x000D_
  min-width: 10px;_x000D_
  width: 20px;_x000D_
  max-width: 20px;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  min-width: 40px;_x000D_
  width: 45px;_x000D_
  max-width: 45px;_x000D_
}_x000D_
_x000D_
.c {}
_x000D_
<table>_x000D_
  <tr>_x000D_
    <td class="a">A</td>_x000D_
    <td class="b">B</td>_x000D_
    <td class="c">C</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

How to convert variable (object) name into String

You can use deparse and substitute to get the name of a function argument:

myfunc <- function(v1) {
  deparse(substitute(v1))
}

myfunc(foo)
[1] "foo"

How to get share counts using graph API

What I found useful and I found on one link above is this FQL query where you ask for likes, total, share and click count of one link by looking at the link_stat table

https://graph.facebook.com/fql?q=SELECT%20like_count,%20total_count,%20share_count,%20click_count,%20comment_count%20FROM%20link_stat%20WHERE%20url%20=%20%22http://google.com%22

That will output something like this:

{
    data: [
        {
             like_count: 3440162,
             total_count: 13226503,
             share_count: 7732740,
             click_count: 265614,
             comment_count: 2053601
         }
    ]
}

How to read if a checkbox is checked in PHP?

I've been using this trick for several years and it works perfectly without any problem for checked/unchecked checkbox status while using with PHP and Database.

HTML Code: (for Add Page)

<input name="status" type="checkbox" value="1" checked>

Hint: remove "checkbox" if you want to show it as unchecked by default

HTML Code: (for Edit Page)

<input name="status" type="checkbox" value="1" 
<?php if ($row['status'] == 1) { echo "checked='checked'"; } ?>>

PHP Code: (use for Add/Edit pages)

$status = $_POST['status'];
if ($status == 1) {
$status = 1;
} else {
$status = 0;
}

Hint: There will always be empty value unless user checked it. So, we already have PHP code to catch it else keep the value to 0. Then, simply use the $status variable for database.

How do you use math.random to generate random ints?

double  i = 2+Math.random()*100;
int j = (int)i;
System.out.print(j);

Why is printing "B" dramatically slower than printing "#"?

Pure speculation is that you're using a terminal that attempts to do word-wrapping rather than character-wrapping, and treats B as a word character but # as a non-word character. So when it reaches the end of a line and searches for a place to break the line, it sees a # almost immediately and happily breaks there; whereas with the B, it has to keep searching for longer, and may have more text to wrap (which may be expensive on some terminals, e.g., outputting backspaces, then outputting spaces to overwrite the letters being wrapped).

But that's pure speculation.

How to echo print statements while executing a sql script

What about using mysql -v to put mysql client in verbose mode ?

Error - replacement has [x] rows, data has [y]

TL;DR ...and late to the party, but that short explanation might help future googlers..

In general that error message means that the replacement doesn't fit into the corresponding column of the dataframe.

A minimal example:

df <- data.frame(a = 1:2); df$a <- 1:3

throws the error

Error in $<-.data.frame(*tmp*, a, value = 1:3) : replacement has 3 rows, data has 2

which is clear, because the vector a of df has 2 entries (rows) whilst the vector we try to replace it has 3 entries (rows).

How can I recognize touch events using jQuery in Safari for iPad? Is it possible?

You can use .on() to capture multiple events and then test for touch on the screen, e.g.:

$('#selector')
.on('touchstart mousedown', function(e){
  e.preventDefault();
  var touch = e.touches[0];
  if(touch){
    // Do some stuff
  }
  else {
    // Do some other stuff
  }
});

What's the best way to use R scripts on the command line (terminal)?

Miguel Sanchez's response is the way it should be. The other way executing Rscript could be 'env' command to run the system wide RScript.

#!/usr/bin/env Rscript

CodeIgniter: How To Do a Select (Distinct Fieldname) MySQL Query

Simple but usefull way:

$query = $this->db->distinct()->select('order_id')->get_where('tbl_order_details', array('seller_id' => $seller_id));
        return $query;

How to parse a String containing XML in Java and retrieve the value of the root node?

There is doing XML reading right, or doing the dodgy just to get by. Doing it right would be using proper document parsing.

Or... dodgy would be using custom text parsing with either wisuzu's response or using regular expressions with matchers.

ValueError: shape mismatch: objects cannot be broadcast to a single shape

This particular error implies that one of the variables being used in the arithmetic on the line has a shape incompatible with another on the same line (i.e., both different and non-scalar). Since n and the output of np.add.reduce() are both scalars, this implies that the problem lies with xm and ym, the two of which are simply your x and y inputs minus their respective means.

Based on this, my guess is that your x and y inputs have different shapes from one another, making them incompatible for element-wise multiplication.

** Technically, it's not that variables on the same line have incompatible shapes. The only problem is when two variables being added, multiplied, etc., have incompatible shapes, whether the variables are temporary (e.g., function output) or not. Two variables with different shapes on the same line are fine as long as something else corrects the issue before the mathematical expression is evaluated.

How to set the first option on a select box using jQuery?

Here is the best solution im using. This will apply for over 1 slectbox

_x000D_
_x000D_
$("select").change(function(){_x000D_
    var thisval = $(this).val();_x000D_
    $("select").prop('selectedIndex',0);_x000D_
    $(this).val(thisval);_x000D_
})
_x000D_
_x000D_
_x000D_

How to stop EditText from gaining focus at Activity startup in Android

Late but simplest answer, just add this in parent layout of the XML.

android:focusable="true" 
android:focusableInTouchMode="true"

Upvote if it helped you ! Happy Coding :)

PHP cURL, extract an XML response

Just add header('Content-type: application/xml'); before your echo of the XML response and you will see an XML page.

How to sort by column in descending order in Spark SQL?

In the case of Java:

If we use DataFrames, while applying joins (here Inner join), we can sort (in ASC) after selecting distinct elements in each DF as:

Dataset<Row> d1 = e_data.distinct().join(s_data.distinct(), "e_id").orderBy("salary");

where e_id is the column on which join is applied while sorted by salary in ASC.

Also, we can use Spark SQL as:

SQLContext sqlCtx = spark.sqlContext();
sqlCtx.sql("select * from global_temp.salary order by salary desc").show();

where

  • spark  -> SparkSession
  • salary -> GlobalTemp View.

CSS Classes & SubClasses

The class you apply on the div can be used to as a reference point to style elements with that div, for example.

<div class="area1">
    <table>
        <tr>
                <td class="item">Text Text Text</td>
                <td class="item">Text Text Text</td>
        </tr>
    </table>
</div>


.area1 { border:1px solid black; }

.area1 td { color:red; } /* This will effect any TD within .area1 */

To be super semantic you should move the class onto the table.

    <table class="area1">
        <tr>
                <td>Text Text Text</td>
                <td>Text Text Text</td>
        </tr>
    </table>

How to import multiple csv files in a single load?

Using Spark 2.0+, we can load multiple CSV files from different directories using df = spark.read.csv(['directory_1','directory_2','directory_3'.....], header=True). For more information, refer the documentation here

Brew install docker does not include docker engine?

The following steps work fine on macOS Sierra 10.12.4. Note that after brew installs Docker, the docker command (symbolic link) is not available at /usr/local/bin. Running the Docker app for the first time creates this symbolic link. See the detailed steps below.

  1. Install Docker.

    brew cask install docker
    
  2. Launch Docker.

    • Press ? + Space to bring up Spotlight Search and enter Docker to launch Docker.
    • In the Docker needs privileged access dialog box, click OK.
    • Enter password and click OK.

    When Docker is launched in this manner, a Docker whale icon appears in the status menu. As soon as the whale icon appears, the symbolic links for docker, docker-compose, docker-credential-osxkeychain and docker-machine are created in /usr/local/bin.

    $ ls -l /usr/local/bin/docker*
    lrwxr-xr-x  1 susam  domain Users  67 Apr 12 14:14 /usr/local/bin/docker -> /Users/susam/Library/Group Containers/group.com.docker/bin/docker
    lrwxr-xr-x  1 susam  domain Users  75 Apr 12 14:14 /usr/local/bin/docker-compose -> /Users/susam/Library/Group Containers/group.com.docker/bin/docker-compose
    lrwxr-xr-x  1 susam  domain Users  90 Apr 12 14:14 /usr/local/bin/docker-credential-osxkeychain -> /Users/susam/Library/Group Containers/group.com.docker/bin/docker-credential-osxkeychain
    lrwxr-xr-x  1 susam  domain Users  75 Apr 12 14:14 /usr/local/bin/docker-machine -> /Users/susam/Library/Group Containers/group.com.docker/bin/docker-machine
    
  3. Click on the docker whale icon in the status menu and wait for it to show Docker is running.

    enter image description here enter image description here

  4. Test that docker works fine.

    $ docker run hello-world
    Unable to find image 'hello-world:latest' locally
    latest: Pulling from library/hello-world
    78445dd45222: Pull complete
    Digest: sha256:c5515758d4c5e1e838e9cd307f6c6a0d620b5e07e6f927b07d05f6d12a1ac8d7
    Status: Downloaded newer image for hello-world:latest
    
    Hello from Docker!
    This message shows that your installation appears to be working correctly.
    
    To generate this message, Docker took the following steps:
     1. The Docker client contacted the Docker daemon.
     2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
     3. The Docker daemon created a new container from that image which runs the
        executable that produces the output you are currently reading.
     4. The Docker daemon streamed that output to the Docker client, which sent it
        to your terminal.
    
    To try something more ambitious, you can run an Ubuntu container with:
     $ docker run -it ubuntu bash
    
    Share images, automate workflows, and more with a free Docker ID:
     https://cloud.docker.com/
    
    For more examples and ideas, visit:
     https://docs.docker.com/engine/userguide/
    
    $ docker version
    Client:
     Version:      17.03.1-ce
     API version:  1.27
     Go version:   go1.7.5
     Git commit:   c6d412e
     Built:        Tue Mar 28 00:40:02 2017
     OS/Arch:      darwin/amd64
    
    Server:
     Version:      17.03.1-ce
     API version:  1.27 (minimum version 1.12)
     Go version:   go1.7.5
     Git commit:   c6d412e
     Built:        Fri Mar 24 00:00:50 2017
     OS/Arch:      linux/amd64
     Experimental: true
    
  5. If you are going to use docker-machine to create virtual machines, install VirtualBox.

    brew cask install virtualbox
    

    Note that if VirtualBox is not installed, then docker-machine fails with the following error.

    $ docker-machine create manager
    Running pre-create checks...
    Error with pre-create check: "VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path"
    

Get started with Latex on Linux

LaTeX comes with most Linux distributions in the form of the teTeX distribution. Find all packages with 'teTeX' in the name and install them.

  • Most editors such as vim or emacs come with TeX editing modes. You can also get WYSIWIG-ish front-ends (technically WYSIWYM), of which perhaps the best known is LyX.

  • The best quick intro to LaTeX is Oetiker's 'The not so short intro to LaTeX'

  • LaTeX works like a compiler. You compile the LaTeX document (which can include other files), which generates a file called a .dvi (device independent). This can be post-processed to various formats (including PDF) with various post-processors.

  • To do PDF, use dvips and use the flag -PPDF (IIRC - I don't have a makefile to hand) to produce a PS with font rendering set up for conversion to pdf. PDF conversion can then be done with ps2pdf or distiller (if you have this).

  • The best format for including graphics in this environment is eps (Encapsulated Postscript) although not all software produces well-behaved postscript. Photographs in jpeg or other formats can be included using various mechanisms.

How to use jQuery with Angular?

Why is everyone making it a rocket science? For anyone else who needs to do some basic stuff on static elements, for example, body tag, just do this:

  1. In index.html add script tag with the path to your jquery lib, doesn't matter where (this way you can also use IE conditional tags to load lower version of jquery for IE9 and less).
  2. In your export component block have a function that calls your code: $("body").addClass("done"); Normaly this causes declaration error, so just after all imports in this .ts file, add declare var $:any; and you are good to go!

How to use protractor to check if an element is visible?

Here are the few code snippet which can be used for framework which use Typescript, protractor, jasmine

browser.wait(until.visibilityOf(OversightAutomationOR.lblContentModal), 3000, "Modal text is present");

// Asserting a text

OversightAutomationOR.lblContentModal.getText().then(text => {
                    this.assertEquals(text.toString().trim(), AdminPanelData.lblContentModal);
                });

// Asserting an element

expect(OnboardingFormsOR.masterFormActionCloneBtn.isDisplayed()).to.eventually.equal(true

    );

OnboardingFormsOR.customFormActionViewBtn.isDisplayed().then((isDisplayed) => {
                        expect(isDisplayed).to.equal(true);
                });

// Asserting a form

formInfoSection.getText().then((text) => {
                        const vendorInformationCount = text[0].split("\n");
                        let found = false;
                        for (let i = 0; i < vendorInformationCount.length; i++) {
                            if (vendorInformationCount[i] === customLabel) {
                                found = true;
                            };
                        };
                        expect(found).to.equal(true);
                    });     

After submitting a POST form open a new window showing the result

If you want to create and submit your form from Javascript as is in your question and you want to create popup window with custom features I propose this solution (I put comments above the lines i added):

var form = document.createElement("form");
form.setAttribute("method", "post");
form.setAttribute("action", "test.jsp");

// setting form target to a window named 'formresult'
form.setAttribute("target", "formresult");

var hiddenField = document.createElement("input");              
hiddenField.setAttribute("name", "id");
hiddenField.setAttribute("value", "bob");
form.appendChild(hiddenField);
document.body.appendChild(form);

// creating the 'formresult' window with custom features prior to submitting the form
window.open('test.html', 'formresult', 'scrollbars=no,menubar=no,height=600,width=800,resizable=yes,toolbar=no,status=no');

form.submit();

How to concatenate int values in java?

How about not using strings at all...

This should work for any number of digits...

int[] nums = {1, 0, 2, 2, 1};

int retval = 0;

for (int digit : nums)
{
    retval *= 10;
    retval += digit;
}

System.out.println("Return value is: " + retval);

Compare string with all values in list

for word in d:
    if d in paid[j]:
         do_something()

will try all the words in the list d and check if they can be found in the string paid[j].

This is not very efficient since paid[j] has to be scanned again for each word in d. You could also use two sets, one composed of the words in the sentence, one of your list, and then look at the intersection of the sets.

sentence = "words don't come easy"
d = ["come", "together", "easy", "does", "it"]

s1 = set(sentence.split())
s2 = set(d)

print (s1.intersection(s2))

Output:

{'come', 'easy'}

Declaring variables inside or outside of a loop

The str variable will be available and reserved some space in memory even after while executed below code.

 String str;
    while(condition){
        str = calculateStr();
        .....
    }

The str variable will not be available and also the memory will be released which was allocated for str variable in below code.

while(condition){
    String str = calculateStr();
    .....
}

If we followed the second one surely this will reduce our system memory and increase performance.

jQuery slide left and show

Don't forget the padding and margins...

jQuery.fn.slideLeftHide = function(speed, callback) { 
  this.animate({ 
    width: "hide", 
    paddingLeft: "hide", 
    paddingRight: "hide", 
    marginLeft: "hide", 
    marginRight: "hide" 
  }, speed, callback);
}

jQuery.fn.slideLeftShow = function(speed, callback) { 
  this.animate({ 
    width: "show", 
    paddingLeft: "show", 
    paddingRight: "show", 
    marginLeft: "show", 
    marginRight: "show" 
  }, speed, callback);
}

With the speed/callback arguments added, it's a complete drop-in replacement for slideUp() and slideDown().

DateTimePicker: pick both date and time

It is best to use two DateTimePickers for the Job One will be the default for the date section and the second DateTimePicker is for the time portion. Format the second DateTimePicker as follows.

      timePortionDateTimePicker.Format = DateTimePickerFormat.Time;
      timePortionDateTimePicker.ShowUpDown = true;

The Two should look like this after you capture them

Two Date Time Pickers

To get the DateTime from both these controls use the following code

DateTime myDate = datePortionDateTimePicker.Value.Date + 
                    timePortionDateTimePicker.Value.TimeOfDay; 

To assign the DateTime to both these controls use the following code

datePortionDateTimePicker.Value  = myDate.Date;  
timePortionDateTimePicker.Value  = myDate.TimeOfDay; 

MVC 4 Razor File Upload

I think, better way is use HttpPostedFileBase in your controller or API. After this you can simple detect size, type etc.

File properties you can find here:

MVC3 How to check if HttpPostedFileBase is an image

For example ImageApi:

[HttpPost]
[Route("api/image")]  
public ActionResult Index(HttpPostedFileBase file)  
{  
    if (file != null && file.ContentLength > 0)  
        try 
        {  
            string path = Path.Combine(Server.MapPath("~/Images"),  
               Path.GetFileName(file.FileName));

            file.SaveAs(path);  
            ViewBag.Message = "Your message for success";  
        }  
        catch (Exception ex)  
        {  
            ViewBag.Message = "ERROR:" + ex.Message.ToString();  
        }  
    else 
    {  
        ViewBag.Message = "Please select file";  
    }  
    return View();  
}

Hope it help.

Run bash script as daemon

You can go to /etc/init.d/ - you will see a daemon template called skeleton.

You can duplicate it and then enter your script under the start function.

How to resize Twitter Bootstrap modal dynamically based on the content

I simply override the css:

.modal-dialog {
    max-width: 1000px;
}

Reset local repository branch to be just like remote repository HEAD

If you want to go back to the HEAD state for both the working directory and the index, then you should git reset --hard HEAD, rather than to HEAD^. (This may have been a typo, just like the single versus double dash for --hard.)

As for your specific question as to why those files appear in the status as modified, it looks like perhaps you did a soft reset instead of a hard reset. This will cause the files that were changed in the HEAD commit to appear as if they were staged, which is likely what you are seeing here.

javascript create array from for loop

You need to push i

var yearStart = 2000;
var yearEnd = 2040;

var arr = [];

for (var i = yearStart; i < yearEnd+1; i++) {
    arr.push(i);
}

Then, your resulting array will be:

arr = [2000, 2001, 2003, ... 2039, 2040]

Hope this helps

Getting Current date, time , day in laravel

Php has a date function which works very well. With laravel and blade you can use this without ugly <?php echo tags. For example, I use the following in a .blade.php file...

Copyright © {{ date('Y') }}

... and Laravel/blade translates that to the current year. If you want date time and day, you'll use something like this:

{{ date('Y-m-d H:i:s') }}

jQuery class within class selector

is just going to look for a div with class="outer inner", is that correct?

No, '.outer .inner' will look for all elements with the .inner class that also have an element with the .outer class as an ancestor. '.outer.inner' (no space) would give the results you're thinking of.

'.outer > .inner' will look for immediate children of an element with the .outer class for elements with the .inner class.

Both '.outer .inner' and '.outer > .inner' should work for your example, although the selectors are fundamentally different and you should be wary of this.

Get the ID of a drawable in ImageView

I think if I understand correctly this is what you are doing.

ImageView view = (ImageView) findViewById(R.id.someImage);
view.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View view) {
        ImageView imageView = (ImageView) view;
        assert(R.id.someImage == imageView.getId());

        switch(getDrawableId(imageView)) {
            case R.drawable.foo:
                imageView.setDrawableResource(R.drawable.bar);
                break;
            case R.drawable.bar:
            default:
                imageView.setDrawableResource(R.drawable.foo);
            break;
        }
    });

Right? So that function getDrawableId() doesn't exist. You can't get a the id that a drawable was instantiated from because the id is just a reference to the location of data on the device on how to construct a drawable. Once the drawable is constructed it doesn't have a way to get back the resourceId that was used to create it. But you could make it work something like this using tags

ImageView view = (ImageView) findViewById(R.id.someImage);
view.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View view) {
        ImageView imageView = (ImageView) view;
        assert(R.id.someImage == imageView.getId());

        // See here
        Integer integer = (Integer) imageView.getTag();
        integer = integer == null ? 0 : integer;

        switch(integer) {
        case R.drawable.foo:
            imageView.setDrawableResource(R.drawable.bar);
            imageView.setTag(R.drawable.bar);
            break;
        case R.drawable.bar:
        default:
            imageView.setDrawableResource(R.drawable.foo);
            imageView.setTag(R.drawable.foo);
            break;
        }
    });

How do I use Spring Boot to serve static content located in Dropbox folder?

@Mark Schäfer

Never too late, but add a slash (/) after static:

spring.resources.static-locations=file:/opt/x/y/z/static/

So http://<host>/index.html is now reachable.

SCP Permission denied (publickey). on EC2 only when using -r flag on directories

The -i flag specifies the private key (.pem file) to use. If you don't specify that flag (as in your first command) it will use your default ssh key (usually under ~/.ssh/).

So in your first command, you are actually asking scp to upload the .pem file itself using your default ssh key. I don't think that is what you want.

Try instead with:

scp -r -i /Applications/XAMPP/htdocs/keypairfile.pem uploads/* ec2-user@publicdns:/var/www/html/uploads

What is the default stack size, can it grow, how does it work with garbage collection?

As you say, local variables and references are stored on the stack. When a method returns, the stack pointer is simply moved back to where it was before the method started, that is, all local data is "removed from the stack". Therefore, there is no garbage collection needed on the stack, that only happens in the heap.

To answer your specific questions:

  • See this question on how to increase the stack size.
  • You can limit the stack growth by:
    • grouping many local variables in an object: that object will be stored in the heap and only the reference is stored on the stack
    • limit the number of nested function calls (typically by not using recursion)
  • For windows, the default stack size is 320k for 32bit and 1024k for 64bit, see this link.

IOException: Too many open files

Don't know the nature of your app, but I have seen this error manifested multiple times because of a connection pool leak, so that would be worth checking out. On Linux, socket connections consume file descriptors as well as file system files. Just a thought.

Function pointer to member function

The syntax is wrong. A member pointer is a different type category from a ordinary pointer. The member pointer will have to be used together with an object of its class:

class A {
public:
 int f();
 int (A::*x)(); // <- declare by saying what class it is a pointer to
};

int A::f() {
 return 1;
}


int main() {
 A a;
 a.x = &A::f; // use the :: syntax
 printf("%d\n",(a.*(a.x))()); // use together with an object of its class
}

a.x does not yet say on what object the function is to be called on. It just says that you want to use the pointer stored in the object a. Prepending a another time as the left operand to the .* operator will tell the compiler on what object to call the function on.

setting JAVA_HOME & CLASSPATH in CentOS 6

Do the following steps:

  1. sudo -s
  2. yum install java-1.8.0-openjdk-devel
  3. vi .bash_profile , and add below line into .bash_profile file and save the file.

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el7_5.x86_64/

Note - I am using CentOS7 as OS.

How to make jQuery UI nav menu horizontal?

I admire all these efforts to convert a menu to a menubar because I detest trying to hack CSS. It just feels like I'm meddling with powers I can't possibly ever understand! I think it's much easier to add the menubar files available at the menubar branch of jquery ui.

I downloaded the full jquery ui css bundled file from the jquery ui download site

In the head of my document I put the jquery ui css file that contains everything (I'm on version 1.9.x at the moment) followed by the specific CSS file for the menubar widget downloaded from the menubar branch of jquery ui

<link type="text/css" href="css/jquery-ui.css" rel="stylesheet" />
<link type="text/css" href="css/jquery.ui.menubar.css" rel="stylesheet" />

Don't forget the images folder with all the little icons used by jQuery UI needs to be in the same folder as the jquery-ui.css file.

Then at the end the body I have:

<script type="text/javascript" src="js/jquery-1.8.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.9.0.custom.min.js"></script>
<script type="text/javascript" src="js/menubar/jquery.ui.menubar.js"></script>

That's a copy of an up-to-date version of jQuery, followed by a copy of the jQuery UI file, then the menubar module downloaded from the menubar branch of jquery ui

The menubar CSS file is refreshingly short:

.ui-menubar { list-style: none; margin: 0; padding-left: 0; }
.ui-menubar-item { float: left; }
.ui-menubar .ui-button { float: left; font-weight: normal; border-top-width: 0 !important; border-bottom-width: 0 !important; margin: 0; outline: none; }
.ui-menubar .ui-menubar-link { border-right: 1px dashed transparent; border-left: 1px dashed transparent; }
.ui-menubar .ui-menu { width: 200px; position: absolute; z-index: 9999; font-weight: normal; }

but the menubar JavaScript file is 328 lines - too long to quote here. With it, you can simply call menubar() like this example:

$("#menu").menubar({
    autoExpand: true,
    menuIcon: true,
    buttons: true,
    select: select
});

As I said, I admire all the attempts to hack the menu object to turn it into a horizontal bar, but I found all of them lacked some standard feature of a horizontal menu bar. I'm not sure why this widget is not bundled with jQuery UI yet, but presumably there are still some bugs to iron out. For instance, I tried it in IE 7 Quirks Mode and the positioning was strange, but it looks great in Firefox, Safari and IE 8+.

What is the difference between JavaScript and ECMAScript?

i know this is an old post but hopefully this will help someone.

In the 1990’s different versions of js started coming out like javascript from netscape, Js script from Microsoft. So ecmascript was introduced as a standard. But ecmascript forms only a part of javascript which specifies its core syntax,types,objects etc. Probably that explains the inconsistent implementations of javascript across diff. browsers

Reference - Wrox(Professional Javascript For Web Developers)

Decimal separator comma (',') with numberDecimal inputType in EditText

Android has a built in number formatter.

You can add this to your EditText to allow decimals and commas: android:inputType="numberDecimal" and android:digits="0123456789.,"

Then somewhere in your code, either when user clicks save or after text is entered (use a listener).

// Format the number to the appropriate double
try { 
    Number formatted = NumberFormat.getInstance().parse(editText.getText().toString());
    cost = formatted.doubleValue();
} catch (ParseException e) {
    System.out.println("Error parsing cost string " + editText.getText().toString());
    cost = 0.0;
}

What does "wrong number of arguments (1 for 0)" mean in Ruby?

You passed an argument to a function which didn't take any. For example:

def takes_no_arguments
end

takes_no_arguments 1
# ArgumentError: wrong number of arguments (1 for 0)

What is the purpose of wrapping whole Javascript files in anonymous functions like “(function(){ … })()”?

That's called a closure. It basically seals the code inside the function so that other libraries don't interfere with it. It's similar to creating a namespace in compiled languages.

Example. Suppose I write:

(function() {

    var x = 2;

    // do stuff with x

})();

Now other libraries cannot access the variable x I created to use in my library.

Shell script : How to cut part of a string

Use a regular expression to catch the id number and replace the whole line with the number. Something like this should do it (match everything up to "id=", then match any number of digits, then match the rest of the line):

sed -e 's/.*id=\([0-9]\+\).*/\1/g'

Do this for every line and you get the list of ids.

Simple Popup by using Angular JS

Built a modal popup example using syarul's jsFiddle link. Here is the updated fiddle.

Created an angular directive called modal and used in html. Explanation:-

HTML

<div ng-controller="MainCtrl" class="container">
  <button ng-click="toggleModal('Success')" class="btn btn-default">Success</button>
  <button ng-click="toggleModal('Remove')" class="btn btn-default">Remove</button>
  <button ng-click="toggleModal('Deny')" class="btn btn-default">Deny</button>
  <button ng-click="toggleModal('Cancel')" class="btn btn-default">Cancel</button>
  <modal visible="showModal">
      Any additional data / buttons
  </modal>
</div>

On button click toggleModal() function is called with the button message as parameter. This function toggles the visibility of popup. Any tags that you put inside will show up in the popup as content since ng-transclude is placed on modal-body in the directive template.

JS

var mymodal = angular.module('mymodal', []);

mymodal.controller('MainCtrl', function ($scope) {
    $scope.showModal = false;
    $scope.buttonClicked = "";
    $scope.toggleModal = function(btnClicked){
        $scope.buttonClicked = btnClicked;
        $scope.showModal = !$scope.showModal;
    };
  });

mymodal.directive('modal', function () {
    return {
      template: '<div class="modal fade">' + 
          '<div class="modal-dialog">' + 
            '<div class="modal-content">' + 
              '<div class="modal-header">' + 
                '<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>' + 
                '<h4 class="modal-title">{{ buttonClicked }} clicked!!</h4>' + 
              '</div>' + 
              '<div class="modal-body" ng-transclude></div>' + 
            '</div>' + 
          '</div>' + 
        '</div>',
      restrict: 'E',
      transclude: true,
      replace:true,
      scope:true,
      link: function postLink(scope, element, attrs) {
        scope.title = attrs.title;

        scope.$watch(attrs.visible, function(value){
          if(value == true)
            $(element).modal('show');
          else
            $(element).modal('hide');
        });

        $(element).on('shown.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = true;
          });
        });

        $(element).on('hidden.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = false;
          });
        });
      }
    };
  });

UPDATE

<!doctype html>
<html ng-app="mymodal">


<body>

<div ng-controller="MainCtrl" class="container">
  <button ng-click="toggleModal('Success')" class="btn btn-default">Success</button>
  <button ng-click="toggleModal('Remove')" class="btn btn-default">Remove</button>
  <button ng-click="toggleModal('Deny')" class="btn btn-default">Deny</button>
  <button ng-click="toggleModal('Cancel')" class="btn btn-default">Cancel</button>
  <modal visible="showModal">
      Any additional data / buttons
  </modal>
</div>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css">
        <!-- Scripts -->
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/js/bootstrap.min.js"></script>

<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>

    <!-- App -->
    <script>
        var mymodal = angular.module('mymodal', []);

mymodal.controller('MainCtrl', function ($scope) {
    $scope.showModal = false;
    $scope.buttonClicked = "";
    $scope.toggleModal = function(btnClicked){
        $scope.buttonClicked = btnClicked;
        $scope.showModal = !$scope.showModal;
    };
  });

mymodal.directive('modal', function () {
    return {
      template: '<div class="modal fade">' + 
          '<div class="modal-dialog">' + 
            '<div class="modal-content">' + 
              '<div class="modal-header">' + 
                '<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>' + 
                '<h4 class="modal-title">{{ buttonClicked }} clicked!!</h4>' + 
              '</div>' + 
              '<div class="modal-body" ng-transclude></div>' + 
            '</div>' + 
          '</div>' + 
        '</div>',
      restrict: 'E',
      transclude: true,
      replace:true,
      scope:true,
      link: function postLink(scope, element, attrs) {
          scope.$watch(attrs.visible, function(value){
          if(value == true)
            $(element).modal('show');
          else
            $(element).modal('hide');
        });

        $(element).on('shown.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = true;
          });
        });

        $(element).on('hidden.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = false;
          });
        });
      }
    };
  });

    </script>
</body>
</html>

UPDATE 2 restrict : 'E' : directive to be used as an HTML tag (element). Example in our case is

<modal>

Other values are 'A' for attribute

<div modal>

'C' for class (not preferable in our case because modal is already a class in bootstrap.css)

<div class="modal">

How to slice a Pandas Data Frame by position?

df.ix[10,:] gives you all the columns from the 10th row. In your case you want everything up to the 10th row which is df.ix[:9,:]. Note that the right end of the slice range is inclusive: http://pandas.sourceforge.net/gotchas.html#endpoints-are-inclusive

Wait for Angular 2 to load/resolve model before rendering view/template

Implement the routerOnActivate in your @Component and return your promise:

https://angular.io/docs/ts/latest/api/router/OnActivate-interface.html

EDIT: This explicitly does NOT work, although the current documentation can be a little hard to interpret on this topic. See Brandon's first comment here for more information: https://github.com/angular/angular/issues/6611

EDIT: The related information on the otherwise-usually-accurate Auth0 site is not correct: https://auth0.com/blog/2016/01/25/angular-2-series-part-4-component-router-in-depth/

EDIT: The angular team is planning a @Resolve decorator for this purpose.

Shell script to copy files from one location to another location and rename add the current date to every file

You can be used this step is very useful:

for i in `ls -l folder1 | grep -v total | awk '{print $ ( ? )}'`
do
   cd folder1
   cp $i folder2/$i.`date +%m%d%Y`
done

How can I git stash a specific file?

To add to svick's answer, the -m option simply adds a message to your stash, and is entirely optional. Thus, the command

git stash push [paths you wish to stash]

is perfectly valid. So for instance, if I want to only stash changes in the src/ directory, I can just run

git stash push src/

How do I check if a cookie exists?

I have crafted an alternative non-jQuery version:

document.cookie.match(/^(.*;)?\s*MyCookie\s*=\s*[^;]+(.*)?$/)

It only tests for cookie existence. A more complicated version can also return cookie value:

value_or_null = (document.cookie.match(/^(?:.*;)?\s*MyCookie\s*=\s*([^;]+)(?:.*)?$/)||[,null])[1]

Put your cookie name in in place of MyCookie.

Running Bash commands in Python

You can use subprocess, but I always felt that it was not a 'Pythonic' way of doing it. So I created Sultan (shameless plug) that makes it easy to run command line functions.

https://github.com/aeroxis/sultan