#Release mode | Programs & Examples on Release mode

Setting the correct encoding when piping stdout in Python

First, regarding this solution:

# -*- coding: utf-8 -*-
print u"åäö".encode('utf-8')

It's not practical to explicitly print with a given encoding every time. That would be repetitive and error-prone.

A better solution is to change sys.stdout at the start of your program, to encode with a selected encoding. Here is one solution I found on Python: How is sys.stdout.encoding chosen?, in particular a comment by "toka":

import sys
import codecs
sys.stdout = codecs.getwriter('utf8')(sys.stdout)

What is the default scope of a method in Java?

Java 8 now allows implementation of methods inside an interface itself with default scope (and static only).

React Native version mismatch

The fix we did was to make sure the ANDROID_HOME and PATH variables were set up prior to the build.

First, run the below two commands then the build the app for the device.

export ANDROID_HOME=/Users/username/MyFiles/applications/androidsdk
export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

PHPDoc type hinting for array of objects?

As DanielaWaranie mentioned in her answer - there is a way to specify the type of $item when you iterating over $items in $collectionObject: Add @return MyEntitiesClassName to current() and rest of the Iterator and ArrayAccess-methods which return values.

Boom! No need in /** @var SomeObj[] $collectionObj */ over foreach, and works right with collection object, no need to return collection with specific method described as @return SomeObj[].

I suspect not all IDE support it but it works perfectly fine in PhpStorm, which makes me happier.

Example:

class MyCollection implements Countable, Iterator, ArrayAccess {

    /**
     * @return User
     */
    public function current() {
        return $this->items[$this->cursor];
    }

    //... implement rest of the required `interface` methods and your custom
}

What useful i was going to add posting this answer

In my case current() and rest of interface-methods are implemented in Abstract-collection class and I do not know what kind of entities will eventually be stored in collection.

So here is the trick: Do not specify return type in abstract class, instead use PhpDoc instuction @method in description of specific collection class.

Example:

class User {

    function printLogin() {
        echo $this->login;
    }

}

abstract class MyCollection implements Countable, Iterator, ArrayAccess {

    protected $items = [];

    public function current() {
        return $this->items[$this->cursor];
    }

    //... implement rest of the required `interface` methods and your custom
    //... abstract methods which will be shared among child-classes
}

/**
 * @method User current()
 * ...rest of methods (for ArrayAccess) if needed
 */
class UserCollection extends MyCollection {

    function add(User $user) {
        $this->items[] = $user;
    }

    // User collection specific methods...

}

Now, usage of classes:

$collection = new UserCollection();
$collection->add(new User(1));
$collection->add(new User(2));
$collection->add(new User(3));

foreach ($collection as $user) {
    // IDE should `recognize` method `printLogin()` here!
    $user->printLogin();
}

Once again: I suspect not all IDE support it, but PhpStorm does. Try yours, post in comment the results!

Auto submit form on page load

Add the following to Body tag,

<body onload="document.forms['member_signup'].submit()">

and give name attribute to your Form.

<form method="POST" action="" name="member_signup">

xls to csv converter

Using xlrd is a flawed way to do this, because you lose the Date Formats in Excel.

My use case is the following.

Take an Excel File with more than one sheet and convert each one into a file of its own.

I have done this using the xlsx2csv library and calling this using a subprocess.

import csv
import sys, os, json, re, time
import subprocess

def csv_from_excel(fname):
    subprocess.Popen(["xlsx2csv " + fname + " --all -d '|' -i -p "
                      "'<New Sheet>' > " + 'test.csv'], shell=True)

    return

lstSheets = csv_from_excel(sys.argv[1])

time.sleep(3) # system needs to wait a second to recognize the file was  written

with open('[YOUR PATH]/test.csv') as f:
    lines = f.readlines()
    firstSheet = True

    for line in lines:
        if line.startswith('<New Sheet>'):
            if firstSheet:
                sh_2_fname = line.replace('<New Sheet>', '').strip().replace(' - ', '_').replace(' ','_')
                print(sh_2_fname)
                sh2f = open(sh_2_fname+".csv", "w")
                firstSheet = False
            else:
                sh2f.close()
                sh_2_fname = line.replace('<New Sheet>', '').strip().replace(' - ', '_').replace(' ','_')
                print(sh_2_fname)
                sh2f = open(sh_2_fname+".csv", "w")
        else:
            sh2f.write(line)
sh2f.close()

How to detect if a stored procedure already exists

From SQL Server 2016 CTP3 you can use new DIE statements instead of big IF wrappers

Syntax:

DROP { PROC | PROCEDURE } [ IF EXISTS ] { [ schema_name. ] procedure } [ ,...n ]

Query:

DROP PROCEDURE IF EXISTS usp_name

More info here

How do I delete everything in Redis?

You can use FLUSHALL which will delete all keys from your every database. Where as FLUSHDB will delete all keys from our current database.

Reading Datetime value From Excel sheet

Another option: when cell type is unknown at compile time and cell is formatted as Date Range.Value returns a desired DateTime object.


public static DateTime? GetAsDateTimeOrDefault(Range cell)
{
    object cellValue = cell.Value;
    if (cellValue is DateTime result)
    {
        return result;
    }
    return null;
}

How do I access properties of a javascript object if I don't know the names?

Old versions of JavaScript (< ES5) require using a for..in loop:

for (var key in data) {
  if (data.hasOwnProperty(key)) {
    // do something with key
  }
}

ES5 introduces Object.keys and Array#forEach which makes this a little easier:

var data = { foo: 'bar', baz: 'quux' };

Object.keys(data); // ['foo', 'baz']
Object.keys(data).map(function(key){ return data[key] }) // ['bar', 'quux']
Object.keys(data).forEach(function (key) {
  // do something with data[key]
});

ES2017 introduces Object.values and Object.entries.

Object.values(data) // ['bar', 'quux']
Object.entries(data) // [['foo', 'bar'], ['baz', 'quux']]

Node.js - How to send data from html to express

I'd like to expand on Obertklep's answer. In his example it is an NPM module called body-parser which is doing most of the work. Where he puts req.body.name, I believe he/she is using body-parser to get the contents of the name attribute(s) received when the form is submitted.

If you do not want to use Express, use querystring which is a built-in Node module. See the answers in the link below for an example of how to use querystring.

It might help to look at this answer, which is very similar to your quest.

Deserializing JSON data to C# using JSON.NET

You can try checking some of the class generators online for further information. However, I believe some of the answers have been useful. Here's my approach that may be useful.

The following code was made with a dynamic method in mind.

dynObj = (JArray) JsonConvert.DeserializeObject(nvm);

foreach(JObject item in dynObj) {
 foreach(JObject trend in item["trends"]) {
  Console.WriteLine("{0}-{1}-{2}", trend["query"], trend["name"], trend["url"]);
 }
}

This code basically allows you to access members contained in the Json string. Just a different way without the need of the classes. query, trend and url are the objects contained in the Json string.

You can also use this website. Don't trust the classes a 100% but you get the idea.

JavaScript onclick redirect

Just do

onclick="SubmitFrm"

The javascript: prefix is only required for link URLs.

Collision resolution in Java HashMap

It could have formed a linked list, indeed. It's just that Map contract requires it to replace the entry:

V put(K key, V value)

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

http://docs.oracle.com/javase/6/docs/api/java/util/Map.html

For a map to store lists of values, it'd need to be a Multimap. Here's Google's: http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/Multimap.html

A collection similar to a Map, but which may associate multiple values with a single key. If you call put(K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values.

Edit: Collision resolution

That's a bit different. A collision happens when two different keys happen to have the same hash code, or two keys with different hash codes happen to map into the same bucket in the underlying array.

Consider HashMap's source (bits and pieces removed):

public V put(K key, V value) {
    int hash = hash(key.hashCode());
    int i = indexFor(hash, table.length);
    // i is the index where we want to insert the new element
    addEntry(hash, key, value, i);
    return null;
}

void addEntry(int hash, K key, V value, int bucketIndex) {
    // take the entry that's already in that bucket
    Entry<K,V> e = table[bucketIndex];
    // and create a new one that points to the old one = linked list
    table[bucketIndex] = new Entry<>(hash, key, value, e);
}

For those who are curious how the Entry class in HashMap comes to behave like a list, it turns out that HashMap defines its own static Entry class which implements Map.Entry. You can see for yourself by viewing the source code:

GrepCode for HashMap

Error - trustAnchors parameter must be non-empty

I got this error when using a truststore which was exported using a IBM Websphere JDK keytool in #PKCS12 format and trying to communicate over SSL using that file on an Oracle JRE.

My solution was to run on an IBM JRE or convert the truststore to JKS using an IBM Websphere keytool, so I was able to run it in an Oracle JRE.

Convert a numpy.ndarray to string(or bytes) and convert it back to numpy.ndarray

This is a fast way to encode the array, the array shape and the array dtype:

def numpy_to_bytes(arr: np.array) -> str:
    arr_dtype = bytearray(str(arr.dtype), 'utf-8')
    arr_shape = bytearray(','.join([str(a) for a in arr.shape]), 'utf-8')
    sep = bytearray('|', 'utf-8')
    arr_bytes = arr.ravel().tobytes()
    to_return = arr_dtype + sep + arr_shape + sep + arr_bytes
    return to_return

def bytes_to_numpy(serialized_arr: str) -> np.array:
    sep = '|'.encode('utf-8')
    i_0 = serialized_arr.find(sep)
    i_1 = serialized_arr.find(sep, i_0 + 1)
    arr_dtype = serialized_arr[:i_0].decode('utf-8')
    arr_shape = tuple([int(a) for a in serialized_arr[i_0 + 1:i_1].decode('utf-8').split(',')])
    arr_str = serialized_arr[i_1 + 1:]
    arr = np.frombuffer(arr_str, dtype = arr_dtype).reshape(arr_shape)
    return arr

To use the functions:

a = np.ones((23, 23), dtype = 'int')
a_b = numpy_to_bytes(a)
a1 = bytes_to_numpy(a_b)
np.array_equal(a, a1) and a.shape == a1.shape and a.dtype == a1.dtype

Javascript onclick hide div

Simple & Best way:

onclick="parentNode.remove()"

Deletes the complete parent from html

Is there a command for formatting HTML in the Atom editor?

There are a few packages for prettifying HTML. You can find them by searching the Atom package archive:

Navigate to the Atom site
Click the Packages link
Enter "prettify" in the search box

Or just go to this link: https://atom.io/packages/search?q=prettify

Once you've selected a package that does what you want you can install it by using the command: apm install [package name] from the command line or install it using the interface in Preferences.

When the package is installed, follow its instructions for how to activate its capabilities.

Visual Studio Code Automatic Imports

I used Auto Import plugin by steoates which is quite easy.

Automatically finds, parses and provides code actions and code completion for all available imports. Works with Typescript and TSX.

How to find the extension of a file in C#?

Path.GetExtension

string myFilePath = @"C:\MyFile.txt";
string ext = Path.GetExtension(myFilePath);
// ext would be ".txt"

Is it better practice to use String.format over string Concatenation in Java?

Which one is more readable depends on how your head works.

You got your answer right there.

It's a matter of personal taste.

String concatenation is marginally faster, I suppose, but that should be negligible.

jQuery add blank option to top of list and make selected to existing dropdown

This worked:

$("#theSelectId").prepend("<option value='' selected='selected'></option>");

Firebug Output:

<select id="theSelectId">
  <option selected="selected" value=""/>
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

You could also use .prependTo if you wanted to reverse the order:

?$("<option>", { value: '', selected: true }).prependTo("#theSelectId");???????????

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CollegeWebsite]]

This error happens because of your Jre version of Eclipse and Tomcat are mismatched ..either change eclipse one to tomcat one or ViceVersa..

Both should be same ..Java version mismatched ..Check it

How to loop through each and every row, column and cells in a GridView and get its value

The easiest would be using a foreach:

foreach(GridViewRow row in GridView2.Rows)
{
    // here you'll get all rows with RowType=DataRow
    // others like Header are omitted in a foreach
}

Edit: According to your edits, you are accessing the column incorrectly, you should start with 0:

foreach(GridViewRow row in GridView2.Rows)
{
    for(int i = 0; i < GridView2.Columns.Count; i++)
    {
        String header = GridView2.Columns[i].HeaderText;
        String cellText = row.Cells[i].Text;
    }
}

Maven is not working in Java 8 when Javadoc tags are incomplete

As of maven-javadoc-plugin 3.0.0 you should have been using additionalJOption to set an additional Javadoc option, so if you would like Javadoc to disable doclint, you should add the following property.

<properties>
    ...
    <additionalJOption>-Xdoclint:none</additionalJOption>
    ...
<properties>

You should also mention the version of maven-javadoc-plugin as 3.0.0 or higher.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-javadoc-plugin</artifactId>
    <version>3.0.0</version>    
</plugin>

JavaScript Extending Class

Summary:

There are multiple ways which can solve the problem of extending a constructor function with a prototype in Javascript. Which of these methods is the 'best' solution is opinion based. However, here are two frequently used methods in order to extend a constructor's function prototype.

ES 2015 Classes:

_x000D_

class Monster {_x000D_
  constructor(health) {_x000D_
    this.health = health_x000D_
  }_x000D_
  _x000D_
  growl () {_x000D_
  console.log("Grr!");_x000D_
  }_x000D_
  _x000D_
}_x000D_
_x000D_
_x000D_
class Monkey extends Monster {_x000D_
  constructor (health) {_x000D_
    super(health) // call super to execute the constructor function of Monster _x000D_
    this.bananaCount = 5;_x000D_
  }_x000D_
}_x000D_
_x000D_
const monkey = new Monkey(50);_x000D_
_x000D_
console.log(typeof Monster);_x000D_
console.log(monkey);

_x000D_

The above approach of using ES 2015 classes is nothing more than syntactic sugar over the prototypal inheritance pattern in javascript. Here the first log where we evaluate typeof Monster we can observe that this is function. This is because classes are just constructor functions under the hood. Nonetheless you may like this way of implementing prototypal inheritance and definitively should learn it. It is used in major frameworks such as ReactJS and Angular2+.

Factory function using `Object.create()`:

_x000D_

function makeMonkey (bananaCount) {_x000D_
  _x000D_
  // here we define the prototype_x000D_
  const Monster = {_x000D_
  health: 100,_x000D_
  growl: function() {_x000D_
  console.log("Grr!");}_x000D_
  }_x000D_
  _x000D_
  const monkey = Object.create(Monster);_x000D_
  monkey.bananaCount = bananaCount;_x000D_
_x000D_
  return monkey;_x000D_
}_x000D_
_x000D_
_x000D_
const chimp = makeMonkey(30);_x000D_
_x000D_
chimp.growl();_x000D_
console.log(chimp.bananaCount);

_x000D_

This method uses the Object.create() method which takes an object which will be the prototype of the newly created object it returns. Therefore we first create the prototype object in this function and then call Object.create() which returns an empty object with the __proto__ property set to the Monster object. After this we can initialize all the properties of the object, in this example we assign the bananacount to the newly created object.

java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory

When you copy dependency from maven repository there is:

<scope>test</scope>

Try to remove it from dependencies in pom.xml like this.

<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.2.3</version>
</dependency>

This works for me. I hope it would be helpful for someone else.

Design Android EditText to show error message as described by google

private EditText edt_firstName;
private String firstName;

edt_firstName = findViewById(R.id.edt_firstName);

private void validateData() {
 firstName = edt_firstName.getText().toString().trim();
 if (!firstName.isEmpty(){
//here api call for ....
}else{
if (firstName.isEmpty()) {
                edt_firstName.setError("Please Enter First Name");
                edt_firstName.requestFocus();
            } 
}
}

Index of Currently Selected Row in DataGridView

Try it:

int rc=dgvDataRc.CurrentCell.RowIndex;** //for find the row index number
MessageBox.Show("Current Row Index is = " + rc.ToString());

I hope it will help you.

Android emulator not able to access the internet

Emulators w Android 9+ worked for me but Android 7 would not connect to the internet.

My office uses Little Snitch application firewall. I turned it off and Android 7 worked. Probably a good idea to check your firewalls.

Why dividing two integers doesn't get a float?

Dividing two integers will result in an integer (whole number) result.

You need to cast one number as a float, or add a decimal to one of the numbers, like a/350.0.

How to access private data members outside the class without making "friend"s?

Bad idea, don't do it ever - but here it is how it can be done:

int main()
{
   A aObj;
   int* ptr;

   ptr = (int*)&aObj;

   // MODIFY!
   *ptr = 100;
}

SQL Query to add a new column after an existing column in SQL Server 2005

It is a bad idea to select * from anything, period. This is why SSMS adds every field name, even if there are hundreds, instead of select *. It is extremely inefficient regardless of how large the table is. If you don't know what the fields are, its still more efficient to pull them out of the INFORMATION_SCHEMA database than it is to select *.

A better query would be:

SELECT 
 COLUMN_NAME, 
 Case 
  When DATA_TYPE In ('varchar', 'char', 'nchar', 'nvarchar', 'binary') 
  Then convert(varchar(MAX), CHARACTER_MAXIMUM_LENGTH)  
  When DATA_TYPE In ('numeric', 'int', 'smallint', 'bigint', 'tinyint') 
  Then convert(varchar(MAX), NUMERIC_PRECISION) 
  When DATA_TYPE = 'bit' 
  Then convert(varchar(MAX), 1)
  When DATA_TYPE IN ('decimal', 'float') 
  Then convert(varchar(MAX), Concat(Concat(NUMERIC_PRECISION, ', '), NUMERIC_SCALE)) 
  When DATA_TYPE IN ('date', 'datetime', 'smalldatetime', 'time', 'timestamp') 
  Then '' 
 End As DATALEN, 
 DATA_TYPE 
FROM INFORMATION_SCHEMA.COLUMNS 
Where 
 TABLE_NAME = ''

Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

You may also find the following approach cleaner than including every method:

class Thing
  delegate :url_helpers, to: 'Rails.application.routes' 

  def url
    url_helpers.thing_path(self)
  end
end

Hard reset of a single file

You can use the following command:

git checkout filename

If you have a branch with the same file name you have to use this command:

git checkout -- filename

Is there a decorator to simply cache function return values?

If you are using Django and want to cache views, see Nikhil Kumar's answer.

But if you want to cache ANY function results, you can use django-cache-utils.

It reuses Django caches and provides easy to use cached decorator:

from cache_utils.decorators import cached

@cached(60)
def foo(x, y=0):
    print 'foo is called'
    return x+y

How to fix curl: (60) SSL certificate: Invalid certificate chain

After updating to OS X 10.9.2, I started having invalid SSL certificate issues with Homebrew, Textmate, RVM, and Github.

When I initiate a brew update, I was getting the following error:

fatal: unable to access 'https://github.com/Homebrew/homebrew/': SSL certificate problem: Invalid certificate chain
Error: Failure while executing: git pull -q origin refs/heads/master:refs/remotes/origin/master

I was able to alleviate some of the issue by just disabling the SSL verification in Git. From the console (a.k.a. shell or terminal):

git config --global http.sslVerify false

I am leary to recommend this because it defeats the purpose of SSL, but it is the only advice I've found that works in a pinch.

I tried rvm osx-ssl-certs update all which stated Already are up to date.

In Safari, I visited https://github.com and attempted to set the certificate manually, but Safari did not present the options to trust the certificate.

Ultimately, I had to Reset Safari (Safari->Reset Safari... menu). Then afterward visit github.com and select the certificate, and "Always trust" This feels wrong and deletes the history and stored passwords, but it resolved my SSL verification issues. A bittersweet victory.

Recursive file search using PowerShell

Here is the method that I finally came up with after struggling:

Get-ChildItem -Recurse -Path path/with/wildc*rds/ -Include file.*

To make the output cleaner (only path), use:

(Get-ChildItem -Recurse -Path path/with/wildc*rds/ -Include file.*).fullname

To get only the first result, use:

(Get-ChildItem -Recurse -Path path/with/wildc*rds/ -Include file.*).fullname | Select -First 1

Now for the important stuff:

To search only for files/directories do not use -File or -Directory (see below why). Instead use this for files:

Get-ChildItem -Recurse -Path ./path*/ -Include name* | where {$_.PSIsContainer -eq $false}

and remove the -eq $false for directories. Do not leave a trailing wildcard like bin/*.

Why not use the built in switches? They are terrible and remove features randomly. For example, in order to use -Include with a file, you must end the path with a wildcard. However, this disables the -Recurse switch without telling you:

Get-ChildItem -File -Recurse -Path ./bin/* -Include *.lib

You'd think that would give you all *.libs in all subdirectories, but it only will search top level of bin.

In order to search for directories, you can use -Directory, but then you must remove the trailing wildcard. For whatever reason, this will not deactivate -Recurse. It is for these reasons that I recommend not using the builtin flags.

You can shorten this command considerably:

Get-ChildItem -Recurse -Path ./path*/ -Include name* | where {$_.PSIsContainer -eq $false}

becomes

gci './path*/' -s -Include 'name*' | where {$_.PSIsContainer -eq $false}

Get-ChildItem is aliased to gci
-Path is default to position 0, so you can just make first argument path
-Recurse is aliased to -s
-Include does not have a shorthand
Use single quotes for spaces in names/paths, so that you can surround the whole command with double quotes and use it in Command Prompt. Doing it the other way around (surround with single quotes) causes errors

Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?

It didn't like my user privilege so I SUDO it. (in bash << sudo set user and password) (this gives username of root and sets the password to nothing) (On Mac)

sudo mysql -uroot -p

The entity type <type> is not part of the model for the current context

One other thing to check with your connection string - the model name. I was using two entity models, DB first. In the config I copied the entity connection for one, renamed it, and changed the connection string part. What I didn't change was the model name, so while the entity model generated correctly, when the context was initiated EF was looking in the wrong model for the entities.

Looks obvious written down, but there are four hours I won't get back.

How to print a list in Python "nicely"

As other answers have mentioned, pprint is a great module that will do what you want. However if you don't want to import it and just want to print debugging output during development, you can approximate its output.

Some of the other answers work fine for strings, but if you try them with a class object it will give you the error TypeError: sequence item 0: expected string, instance found.

For more complex objects, make sure the class has a __repr__ method that prints the property information you want:

class Foo(object):
    def __init__(self, bar):
        self.bar = bar

    def __repr__(self):
        return "Foo - (%r)" % self.bar

And then when you want to print the output, simply map your list to the str function like this:

l = [Foo(10), Foo(20), Foo("A string"), Foo(2.4)]
print "[%s]" % ",\n ".join(map(str,l))

outputs:

 [Foo - (10),
  Foo - (20),
  Foo - ('A string'),
  Foo - (2.4)]

You can also do things like override the __repr__ method of list to get a form of nested pretty printing:

class my_list(list):
    def __repr__(self):
        return "[%s]" % ",\n ".join(map(str, self))

a = my_list(["first", 2, my_list(["another", "list", "here"]), "last"])
print a

gives

[first,
 2,
 [another,
 list,
 here],
 last]

Unfortunately no second-level indentation but for a quick debug it can be useful.

How to find if element with specific id exists or not

You need to specify which object you're calling getElementById from. In this case you can use document. You also can't just call .value on any element directly. For example if the element is textbox .value will return the value, but if it's a div it will not have a value.

You also have a wrong condition, you're checking

if (myEle == null)

which you should change to

if (myEle != null)

var myEle = document.getElementById("myElement");
if(myEle != null) { 
    var myEleValue= myEle.value; 
}

jQuery to retrieve and set selected option value of html select element

The way you have it is correct at the moment. Either the id of the select is not what you say or you have some issues in the dom.

Check the Id of the element and also check your markup validates at here at W3c.

Without a valid dom jQuery cannot work correctly with the selectors.

If the id's are correct and your dom validates then the following applies:

To Read Select Option Value

$('#selectId').val();

To Set Select Option Value

$('#selectId').val('newValue');

To Read Selected Text

$('#selectId>option:selected').text();

Accessing JSON object keys having spaces

The way to do this is via the bracket notation.

_x000D_

var test = {_x000D_
    "id": "109",_x000D_
    "No. of interfaces": "4"_x000D_
}_x000D_
alert(test["No. of interfaces"]);

_x000D_

For more info read out here:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects

How to trap on UIViewAlertForUnsatisfiableConstraints?

Whenever I attempt to remove the constraints that the system had to break, my constraints are no longer enough to satisfy the IB (ie "missing constraints" shows in the IB, which means they're incomplete and won't be used). I actually got around this by setting the constraint it wants to break to low priority, which (and this is an assumption) allows the system to break the constraint gracefully. It's probably not the best solution, but it solved my problem and the resulting constraints worked perfectly.

Ruby String to Date Conversion

Date.strptime(updated,"%a, %d %m %Y %H:%M:%S %Z")

Should be:

Date.strptime(updated, '%a, %d %b %Y %H:%M:%S %Z')

How to use range-based for() loop with std::map?

If copy assignment operator of foo and bar is cheap (eg. int, char, pointer etc), you can do the following:

foo f; bar b;
BOOST_FOREACH(boost::tie(f,b),testing)
{
  cout << "Foo is " << f << " Bar is " << b;
}

From a Sybase Database, how I can get table description ( field names and types)?

In the Sybase version I use, the following gives list of columns for selected table

select *
FROM sys.syscolumns sc
where tname = 'YOUR_TABLE_NAME'
--and creator='YOUR_USER_NAME' --if you want to further restrict tables
--according to the user name that created it

Conditional replacement of values in a data.frame

Since you are conditionally indexing df$est, you also need to conditionally index the replacement vector df$a:

index <- df$b == 0
df$est[index] <- (df$a[index] - 5)/2.533

Of course, the variable index is just temporary, and I use it to make the code a bit more readible. You can write it in one step:

df$est[df$b == 0] <- (df$a[df$b == 0] - 5)/2.533

For even better readibility, you can use within:

df <- within(df, est[b==0] <- (a[b==0]-5)/2.533)

The results, regardless of which method you choose:

df
          a b      est
1  11.77000 2 0.000000
2  10.90000 3 0.000000
3  10.32000 2 0.000000
4  10.96000 0 2.352941
5   9.90600 0 1.936834
6  10.70000 0 2.250296
7  11.43000 1 0.000000
8  11.41000 2 0.000000
9  10.48512 4 0.000000
10 11.19000 0 2.443743

As others have pointed out, an alternative solution in your example is to use ifelse.

What is the difference between .NET Core and .NET Standard Class Library project types?

When should we use one over the other?

The decision is a trade-off between compatibility and API access.

Use a .NET Standard library when you want to increase the number of applications that will be compatible with your library, and you are okay with a decrease in the .NET API surface area your library can access.

Use a .NET Core library when you want to increase the .NET API surface area your library can access, and you are okay with allowing only .NET Core applications to be compatible with your library.

For example, a library that targets .NET Standard 1.3 will be compatible with applications that target .NET Framework 4.6, .NET Core 1.0, Universal Windows Platform 10.0, and any other platform that supports .NET Standard 1.3. The library will not have access to some parts of the .NET API, though. For instance, the Microsoft.NETCore.CoreCLR package is compatible with .NET Core, but not with .NET Standard.

What is the difference between Class Library (.NET Standard) and Class Library (.NET Core)?

Compatibility: Libraries that target .NET Standard will run on any .NET Standard compliant runtime, such as .NET Core, .NET Framework, Mono/Xamarin. On the other hand, libraries that target .NET Core can only run on the .NET Core runtime.

API Surface Area: .NET Standard libraries come with everything in NETStandard.Library, whereas .NET Core libraries come with everything in Microsoft.NETCore.App. The latter includes approximately 20 additional libraries, some of which we can add manually to our .NET Standard library (such as System.Threading.Thread) and some of which are not compatible with the .NET Standard (such as Microsoft.NETCore.CoreCLR).

Also, .NET Core libraries specify a runtime and come with an application model. That's important, for instance, to make unit test class libraries runnable.

Why do both exist?

Ignoring libraries for a moment, the reason that .NET Standard exists is for portability; it defines a set of APIs that .NET platforms agree to implement. Any platform that implements a .NET Standard is compatible with libraries that target that .NET Standard. One of those compatible platforms is .NET Core.

Coming back to libraries, the .NET Standard library templates exist to run on multiple runtimes (at the expense of API surface area). Conversely, the .NET Core library templates exist to access more API surface area (at the expense of compatibility) and to specify a platform against which to build an executable.

Here is an interactive matrix that shows which .NET Standard supports which .NET implementation(s) and how much API surface area is available.

What's the difference between SortedList and SortedDictionary?

This is visual representation of how performances compare to each other.

What is the use of static synchronized method in java?

In general, synchronized methods are used to protect access to resources that are accessed concurrently. When a resource that is being accessed concurrently belongs to each instance of your class, you use a synchronized instance method; when the resource belongs to all instances (i.e. when it is in a static variable) then you use a synchronized static method to access it.

For example, you could make a static factory method that keeps a "registry" of all objects that it has produced. A natural place for such registry would be a static collection. If your factory is used from multiple threads, you need to make the factory method synchronized (or have a synchronized block inside the method) to protect access to the shared static collection.

Note that using synchronized without a specific lock object is generally not the safest choice when you are building a library to be used in code written by others. This is because malicious code could synchronize on your object or a class to block your own methods from executing. To protect your code against this, create a private "lock" object, instance or static, and synchronize on that object instead.

Why am I getting "IndentationError: expected an indented block"?

I had this same problem and discovered (via this answer to a similar question) that the problem was that I didn't properly indent the docstring properly. Unfortunately IDLE doesn't give useful feedback here, but once I fixed the docstring indentation, the problem went away.

Specifically --- bad code that generates indentation errors:

def my_function(args):
"Here is my docstring"
    ....

Good code that avoids indentation errors:

def my_function(args):
    "Here is my docstring"
    ....

Note: I'm not saying this is the problem, but that it might be, because in my case, it was!

How to retrieve GET parameters from JavaScript

With the window.location object. This code gives you GET without the question mark.

window.location.search.substr(1)

From your example it will return returnurl=%2Fadmin

EDIT: I took the liberty of changing Qwerty's answer, which is really good, and as he pointed I followed exactly what the OP asked:

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    location.search
        .substr(1)
        .split("&")
        .forEach(function (item) {
          tmp = item.split("=");
          if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
        });
    return result;
}

I removed the duplicated function execution from his code, replacing it a variable ( tmp ) and also I've added decodeURIComponent, exactly as OP asked. I'm not sure if this may or may not be a security issue.

Or otherwise with plain for loop, which will work even in IE8:

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    var items = location.search.substr(1).split("&");
    for (var index = 0; index < items.length; index++) {
        tmp = items[index].split("=");
        if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
    }
    return result;
}

Express.js req.body undefined

adding express.urlencoded({ extended: true }) to the route solves the problem.

router.post('/save',express.urlencoded({ extended: true }),  "your route");

Openstreetmap: embedding map in webpage (like Google Maps)

I would also take a look at CloudMade's developer tools. They offer a beautifully styled OSM base map service, an OpenLayers plugin, and even their own light-weight, very fast JavaScript mapping client. They also host their own routing service, which you mentioned as a possible requirement. They have great documentation and examples.

Oracle 10g: Extract data (select) from XML (CLOB Type)

this query runs perfectly in my case

select xmltype(t.axi_content).extract('//Lexis-NexisFlag/text()').getStringVal() from ax_bib_entity t

How to call a function within class?

That doesn't work because distToPoint is inside your class, so you need to prefix it with the classname if you want to refer to it, like this: classname.distToPoint(self, p). You shouldn't do it like that, though. A better way to do it is to refer to the method directly through the class instance (which is the first argument of a class method), like so: self.distToPoint(p).

How to install beautiful soup 4 with python 2.7 on windows

easy_install BeautifulSoup4

easy_install BeautifulSoup

to install easy_install

http://pypi.python.org/pypi/setuptools#files

Vertically aligning text next to a radio button

You need to align the text to the left of radio button using float:left

input[type="radio"]{
float:left;
}

You may use label too for more responsive output.

IsNullOrEmpty with Object

Why would you need any other way? Comparing an Object reference with null is the least-verbose way to check if it's null.

How to manage local vs production settings in Django?

As an alternative to maintain different file if you wiil: If you are using git or any other VCS to push codes from local to server, what you can do is add the settings file to .gitignore.

This will allow you to have different content in both places without any problem. SO on server you can configure an independent version of settings.py and any changes made on the local wont reflect on server and vice versa.

In addition, it will remove the settings.py file from github also, the big fault, which i have seen many newbies doing.

Change DataGrid cell colour based on values

To do this in the Code Behind (VB.NET)

Dim txtCol As New DataGridTextColumn

Dim style As New Style(GetType(TextBlock))
Dim tri As New Trigger With {.Property = TextBlock.TextProperty, .Value = "John"}
tri.Setters.Add(New Setter With {.Property = TextBlock.BackgroundProperty, .Value = Brushes.Green})
style.Triggers.Add(tri)

xtCol.ElementStyle = style

Javascript isnull

Why not try .test() ? ... Try its and best boolean (true or false):

$.urlParam = function(name){
    var results = new RegExp('[\\?&]' + name + '=([^&#]*)');
    return results.test(window.location.href);
}

Tutorial: http://www.w3schools.com/jsref/jsref_regexp_test.asp

JQuery Calculate Day Difference in 2 date textboxes

This should do the trick

var start = $('#start_date').val();
var end = $('#end_date').val();

// end - start returns difference in milliseconds 
var diff = new Date(end - start);

// get days
var days = diff/1000/60/60/24;

Example

var start = new Date("2010-04-01"),
    end   = new Date(),
    diff  = new Date(end - start),
    days  = diff/1000/60/60/24;

days; //=> 8.525845775462964

How to get child element by class name?

You could try:

notes = doc.querySelectorAll('.4');

notes = doc.getElementsByTagName('*');
for (var i = 0; i < notes.length; i++) { 
    if (notes[i].getAttribute('class') == '4') {
    }
}

In nodeJs is there a way to loop through an array without using array size?

    var count=0;
    let myArray = '{"1":"a","2":"b","3":"c","4":"d"}'
    var data = JSON.parse(myArray);
    for (let key in data) {
      let value =  data[key]; // get the value by key
      console.log("key: , value:", key, value);
      count = count + 1;
    }
   console.log("size:",count);

How to use Git?

Have a look at git for designers for great one page article/high level intro to the topic. (That link is broken: Here is a link to another Git for Designers )

I would start at http://git-scm.com/documentation, there are documents and great video presentations for non-software-developer/cs users. Git for beginners have some basic stuff.

How to find the mime type of a file in python?

python 3 ref: https://docs.python.org/3.2/library/mimetypes.html

mimetypes.guess_type(url, strict=True) Guess the type of a file based on its filename or URL, given by url. The return value is a tuple (type, encoding) where type is None if the type can’t be guessed (missing or unknown suffix) or a string of the form 'type/subtype', usable for a MIME content-type header.

encoding is None for no encoding or the name of the program used to encode (e.g. compress or gzip). The encoding is suitable for use as a Content-Encoding header, not as a Content-Transfer-Encoding header. The mappings are table driven. Encoding suffixes are case sensitive; type suffixes are first tried case sensitively, then case insensitively.

The optional strict argument is a flag specifying whether the list of known MIME types is limited to only the official types registered with IANA. When strict is True (the default), only the IANA types are supported; when strict is False, some additional non-standard but commonly used MIME types are also recognized.

import mimetypes
print(mimetypes.guess_type("sample.html"))

How do I compile a Visual Studio project from the command-line?

To be honest I have to add my 2 cents.

You can do it with msbuild.exe. There are many version of the msbuild.exe.

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\msbuild.exe C:\Windows\Microsoft.NET\Framework64\v3.5\msbuild.exe C:\Windows\Microsoft.NET\Framework64\v4.0.30319\msbuild.exe
C:\Windows\Microsoft.NET\Framework\v2.0.50727\msbuild.exe C:\Windows\Microsoft.NET\Framework\v3.5\msbuild.exe C:\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe

Use version you need. Basically you have to use the last one.

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\msbuild.exe

So how to do it.

Run the COMMAND window
Input the path to msbuild.exe

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\msbuild.exe

Input the path to the project solution like

"C:\Users\Clark.Kent\Documents\visual studio 2012\Projects\WpfApplication1\WpfApplication1.sln"

Add any flags you need after the solution path.
Press ENTER

Note you can get help about all possible flags like

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\msbuild.exe /help

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.

ANTLR: Is there a simple example?

Note: this answer is for ANTLR3! If you're looking for an ANTLR4 example, then this Q&A demonstrates how to create a simple expression parser, and evaluator using ANTLR4.

You first create a grammar. Below is a small grammar that you can use to evaluate expressions that are built using the 4 basic math operators: +, -, * and /. You can also group expressions using parenthesis.

Note that this grammar is just a very basic one: it does not handle unary operators (the minus in: -1+9) or decimals like .99 (without a leading number), to name just two shortcomings. This is just an example you can work on yourself.

Here's the contents of the grammar file Exp.g:

grammar Exp;

/* This will be the entry point of our parser. */
eval
    :    additionExp
    ;

/* Addition and subtraction have the lowest precedence. */
additionExp
    :    multiplyExp 
         ( '+' multiplyExp 
         | '-' multiplyExp
         )* 
    ;

/* Multiplication and division have a higher precedence. */
multiplyExp
    :    atomExp
         ( '*' atomExp 
         | '/' atomExp
         )* 
    ;

/* An expression atom is the smallest part of an expression: a number. Or 
   when we encounter parenthesis, we're making a recursive call back to the
   rule 'additionExp'. As you can see, an 'atomExp' has the highest precedence. */
atomExp
    :    Number
    |    '(' additionExp ')'
    ;

/* A number: can be an integer value, or a decimal value */
Number
    :    ('0'..'9')+ ('.' ('0'..'9')+)?
    ;

/* We're going to ignore all white space characters */
WS  
    :   (' ' | '\t' | '\r'| '\n') {$channel=HIDDEN;}
    ;

(Parser rules start with a lower case letter, and lexer rules start with a capital letter)

After creating the grammar, you'll want to generate a parser and lexer from it. Download the ANTLR jar and store it in the same directory as your grammar file.

Execute the following command on your shell/command prompt:

java -cp antlr-3.2.jar org.antlr.Tool Exp.g

It should not produce any error message, and the files ExpLexer.java, ExpParser.java and Exp.tokens should now be generated.

To see if it all works properly, create this test class:

import org.antlr.runtime.*;

public class ANTLRDemo {
    public static void main(String[] args) throws Exception {
        ANTLRStringStream in = new ANTLRStringStream("12*(5-6)");
        ExpLexer lexer = new ExpLexer(in);
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        ExpParser parser = new ExpParser(tokens);
        parser.eval();
    }
}

and compile it:

// *nix/MacOS
javac -cp .:antlr-3.2.jar ANTLRDemo.java

// Windows
javac -cp .;antlr-3.2.jar ANTLRDemo.java

and then run it:

// *nix/MacOS
java -cp .:antlr-3.2.jar ANTLRDemo

// Windows
java -cp .;antlr-3.2.jar ANTLRDemo

If all goes well, nothing is being printed to the console. This means the parser did not find any error. When you change "12*(5-6)" into "12*(5-6" and then recompile and run it, there should be printed the following:

line 0:-1 mismatched input '<EOF>' expecting ')'

Okay, now we want to add a bit of Java code to the grammar so that the parser actually does something useful. Adding code can be done by placing { and } inside your grammar with some plain Java code inside it.

But first: all parser rules in the grammar file should return a primitive double value. You can do that by adding returns [double value] after each rule:

grammar Exp;

eval returns [double value]
    :    additionExp
    ;

additionExp returns [double value]
    :    multiplyExp 
         ( '+' multiplyExp 
         | '-' multiplyExp
         )* 
    ;

// ...

which needs little explanation: every rule is expected to return a double value. Now to "interact" with the return value double value (which is NOT inside a plain Java code block {...}) from inside a code block, you'll need to add a dollar sign in front of value:

grammar Exp;

/* This will be the entry point of our parser. */
eval returns [double value]                                                  
    :    additionExp { /* plain code block! */ System.out.println("value equals: "+$value); }
    ;

// ...

Here's the grammar but now with the Java code added:

grammar Exp;

eval returns [double value]
    :    exp=additionExp {$value = $exp.value;}
    ;

additionExp returns [double value]
    :    m1=multiplyExp       {$value =  $m1.value;} 
         ( '+' m2=multiplyExp {$value += $m2.value;} 
         | '-' m2=multiplyExp {$value -= $m2.value;}
         )* 
    ;

multiplyExp returns [double value]
    :    a1=atomExp       {$value =  $a1.value;}
         ( '*' a2=atomExp {$value *= $a2.value;} 
         | '/' a2=atomExp {$value /= $a2.value;}
         )* 
    ;

atomExp returns [double value]
    :    n=Number                {$value = Double.parseDouble($n.text);}
    |    '(' exp=additionExp ')' {$value = $exp.value;}
    ;

Number
    :    ('0'..'9')+ ('.' ('0'..'9')+)?
    ;

WS  
    :   (' ' | '\t' | '\r'| '\n') {$channel=HIDDEN;}
    ;

and since our eval rule now returns a double, change your ANTLRDemo.java into this:

import org.antlr.runtime.*;

public class ANTLRDemo {
    public static void main(String[] args) throws Exception {
        ANTLRStringStream in = new ANTLRStringStream("12*(5-6)");
        ExpLexer lexer = new ExpLexer(in);
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        ExpParser parser = new ExpParser(tokens);
        System.out.println(parser.eval()); // print the value
    }
}

Again (re) generate a fresh lexer and parser from your grammar (1), compile all classes (2) and run ANTLRDemo (3):

// *nix/MacOS
java -cp antlr-3.2.jar org.antlr.Tool Exp.g   // 1
javac -cp .:antlr-3.2.jar ANTLRDemo.java      // 2
java -cp .:antlr-3.2.jar ANTLRDemo            // 3

// Windows
java -cp antlr-3.2.jar org.antlr.Tool Exp.g   // 1
javac -cp .;antlr-3.2.jar ANTLRDemo.java      // 2
java -cp .;antlr-3.2.jar ANTLRDemo            // 3

and you'll now see the outcome of the expression 12*(5-6) printed to your console!

Again: this is a very brief explanation. I encourage you to browse the ANTLR wiki and read some tutorials and/or play a bit with what I just posted.

Good luck!

EDIT:

This post shows how to extend the example above so that a Map<String, Double> can be provided that holds variables in the provided expression.

To get this code working with a current version of Antlr (June 2014) I needed to make a few changes. ANTLRStringStream needed to become ANTLRInputStream, the returned value needed to change from parser.eval() to parser.eval().value, and I needed to remove the WS clause at the end, because attribute values such as $channel are no longer allowed to appear in lexer actions.

ImportError: DLL load failed: %1 is not a valid Win32 application

When I had this error, it went away after I my computer crashed and restarted. Try closing and reopening your IDE, if that doesn't work, try restarting your computer. I had just installed the libraries at that point without restarting pycharm when I got this error.

Never closed PyCharm first to test because my blasted computer keeps crashing randomly... working on that one, but it at least solved this problem.. little victories.. :).

How to get anchor text/href on click using jQuery?

Updated code

$('a','div.res').click(function(){
  var currentAnchor = $(this);
  alert(currentAnchor.text());
  alert(currentAnchor.attr('href'));
});

Can't concat bytes to str

You can convert type of plaintext to string:

f.write(str(plaintext) + '\n')

Unable to copy file - access to the path is denied

I was able to resolve the problem by removing the target file which is complaining(in your example "Bin\Debug\test.Resources.xml") from bin folder of target web site and re build it.That fixed it for me.

How to convert a .eps file to a high quality 1024x1024 .jpg?

For vector graphics, ImageMagick has both a render resolution and an output size that are independent of each other.

Try something like

convert -density 300 image.eps -resize 1024x1024 image.jpg

Which will render your eps at 300dpi. If 300 * width > 1024, then it will be sharp. If you render it too high though, you waste a lot of memory drawing a really high-res graphic only to down sample it again. I don't currently know of a good way to render it at the "right" resolution in one IM command.

The order of the arguments matters! The -density X argument needs to go before image.eps because you want to affect the resolution that the input file is rendered at.

This is not super obvious in the manpage for convert, but is hinted at:

SYNOPSIS

convert [input-option] input-file [output-option] output-file

Calculating the difference between two Java date instances

Using millisecond approach can cause problems in some locales.

Lets take, for example, the difference between the two dates 03/24/2007 and 03/25/2007 should be 1 day;

However, using the millisecond route, you'll get 0 days, if you run this in the UK!

/** Manual Method - YIELDS INCORRECT RESULTS - DO NOT USE**/  
/* This method is used to find the no of days between the given dates */  
public long calculateDays(Date dateEarly, Date dateLater) {  
   return (dateLater.getTime() - dateEarly.getTime()) / (24 * 60 * 60 * 1000);  
}

Better way to implement this is to use java.util.Calendar

/** Using Calendar - THE CORRECT WAY**/  
public static long daysBetween(Calendar startDate, Calendar endDate) {  
  Calendar date = (Calendar) startDate.clone();  
  long daysBetween = 0;  
  while (date.before(endDate)) {  
    date.add(Calendar.DAY_OF_MONTH, 1);  
    daysBetween++;  
  }  
  return daysBetween;  
}

How to convert text column to datetime in SQL

In SQL Server , cast text as datetime

select cast('5/21/2013 9:45:48' as datetime)

Catching FULL exception message

The following worked well for me

try {
    asdf
} catch {
    $string_err = $_ | Out-String
}

write-host $string_err

The result of this is the following as a string instead of an ErrorRecord object

asdf : The term 'asdf' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\Users\TASaif\Desktop\tmp\catch_exceptions.ps1:2 char:5
+     asdf
+     ~~~~
    + CategoryInfo          : ObjectNotFound: (asdf:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Determine if a String is an Integer in Java

Or you can enlist a little help from our good friends at Apache Commons : StringUtils.isNumeric(String str)

Specifying onClick event type with Typescript and React.Konva

Taken from the ReactKonvaCore.d.ts file:

onClick?(evt: Konva.KonvaEventObject<MouseEvent>): void;

So, I'd say your event type is Konva.KonvaEventObject<MouseEvent>

Search and replace part of string in database

I would consider writing a CLR replace function with RegEx support for this kind of string manipulation.

text-align:center won't work with form <label> tag (?)

label is an inline element so its width is equal to the width of the text it contains. The browser is actually displaying the label with text-align:center but since the label is only as wide as the text you don't notice.

The best thing to do is to apply a specific width to the label that is greater than the width of the content - this will give you the results you want.

Sort hash by key, return hash in Ruby

You gave the best answer to yourself in the OP: Hash[h.sort] If you crave for more possibilities, here is in-place modification of the original hash to make it sorted:

h.keys.sort.each { |k| h[k] = h.delete k }

What is the purpose of .PHONY in a Makefile?

I often use them to tell the default target not to fire.

superclean: clean andsomethingelse

blah: superclean

clean:
   @echo clean

%:
   @echo catcher $@

.PHONY: superclean

Without PHONY, make superclean would fire clean, andsomethingelse, and catcher superclean; but with PHONY, make superclean won't fire the catcher superclean.

We don't have to worry about telling make the clean target is PHONY, because it isn't completely phony. Though it never produces the clean file, it has commands to fire so make will think it's a final target.

However, the superclean target really is phony, so make will try to stack it up with anything else that provides deps for the superclean target — this includes other superclean targets and the % target.

Note that we don't say anything at all about andsomethingelse or blah, so they clearly go to the catcher.

The output looks something like this:

$ make clean
clean

$ make superclean
clean
catcher andsomethingelse

$ make blah 
clean
catcher andsomethingelse
catcher blah

How to split page into 4 equal parts?

Demo at http://jsfiddle.net/CRSVU/

_x000D_

html,
body {
  height: 100%;
  padding: 0;
  margin: 0;
}

div {
  width: 50%;
  height: 50%;
  float: left;
}

#div1 {
  background: #DDD;
}

#div2 {
  background: #AAA;
}

#div3 {
  background: #777;
}

#div4 {
  background: #444;
}

_x000D_

<div id="div1"></div>
<div id="div2"></div>
<div id="div3"></div>
<div id="div4"></div>

_x000D_

How do I create executable Java program?

Take a look at WinRun4J. It's windows only but that's because unix has executable scripts that look (to the user) like bins. You can also easily modify WinRun4J to compile on unix.

It does require a config file, but again, recompile it with hard-coded options and it works like a config-less exe.

Print a string as hex bytes?

Using base64.b16encode in python2 (its built-in)

>>> s = 'Hello world !!'
>>> h = base64.b16encode(s)
>>> ':'.join([h[i:i+2] for i in xrange(0, len(h), 2)]
'48:65:6C:6C:6F:20:77:6F:72:6C:64:20:21:21'

DataGridView - how to set column width?

I you dont want to do it programmatically, you can manipulate to the Column width property, which is located inside the Columns property.Once you open the column edit property you can choose which column you want to edit, scroll down to layout section of the bound column properties and change the width.

Convert seconds into days, hours, minutes and seconds

Based on the answer by Julian Moreno, but changed to give the response as a string (not an array), only include the time intervals required and not assume the plural.

The difference between this and the highest voted answer is:

For 259264 seconds, this code would give

3 days, 1 minute, 4 seconds

For 259264 seconds, the highest voted answer (by Glavic) would give

3 days, 0 hours, 1 minutes and 4 seconds

function secondsToTime($inputSeconds) {
    $secondsInAMinute = 60;
    $secondsInAnHour = 60 * $secondsInAMinute;
    $secondsInADay = 24 * $secondsInAnHour;

    // Extract days
    $days = floor($inputSeconds / $secondsInADay);

    // Extract hours
    $hourSeconds = $inputSeconds % $secondsInADay;
    $hours = floor($hourSeconds / $secondsInAnHour);

    // Extract minutes
    $minuteSeconds = $hourSeconds % $secondsInAnHour;
    $minutes = floor($minuteSeconds / $secondsInAMinute);

    // Extract the remaining seconds
    $remainingSeconds = $minuteSeconds % $secondsInAMinute;
    $seconds = ceil($remainingSeconds);

    // Format and return
    $timeParts = [];
    $sections = [
        'day' => (int)$days,
        'hour' => (int)$hours,
        'minute' => (int)$minutes,
        'second' => (int)$seconds,
    ];

    foreach ($sections as $name => $value){
        if ($value > 0){
            $timeParts[] = $value. ' '.$name.($value == 1 ? '' : 's');
        }
    }

    return implode(', ', $timeParts);
}

I hope this helps someone.

Run PowerShell scripts on remote PC

After further investigating on PSExec tool, I think I got the answer. I need to add -i option to tell PSExec to launch process on remote in interactive mode:

PSExec \\RPC001 -i -u myID -p myPWD PowerShell C:\script\StartPS.ps1 par1 par2

Without -i, powershell.exe is running on the remote in waiting mode. Interesting point is that if I run a simple bat (without PS in bat), it works fine. Maybe this is something special for PS case? Welcome comments and explanations.

Default username password for Tomcat Application Manager

The admin and manager apps are two separate things. Here's a snapshot of a tomcat-users.xml file that works, try this:

<?xml version='1.0' encoding='utf-8'?>  
<tomcat-users>  
    <role rolename="tomcat"/>  
    <role rolename="role1"/>  
    <role rolename="manager"/>  
    <user username="tomcat" password="tomcat" roles="tomcat"/>  
    <user username="both" password="tomcat" roles="tomcat,role1"/>  
    <user username="role1" password="tomcat" roles="role1"/>  
    <user username="USERNAME" password="PASSWORD" roles="manager,tomcat,role1"/>  
</tomcat-users>

It works for me very well

How to display raw JSON data on a HTML page

JSON in any HTML tag except <script> tag would be a mere text. Thus it's like you add a story to your HTML page.

However, about formatting, that's another matter. I guess you should change the title of your question.

Take a look at this question. Also see this page.

What's the difference between equal?, eql?, ===, and ==?

I love jtbandes answer, but since it is pretty long, I will add my own compact answer:

==, ===, eql?, equal?
are 4 comparators, ie. 4 ways to compare 2 objects, in Ruby.
As, in Ruby, all comparators (and most operators) are actually method-calls, you can change, overwrite, and define the semantics of these comparing methods yourself. However, it is important to understand, when Ruby's internal language constructs use which comparator:

== (value comparison)
Ruby uses :== everywhere to compare the values of 2 objects, eg. Hash-values:

{a: 'z'}  ==  {a: 'Z'}    # => false
{a: 1}    ==  {a: 1.0}    # => true

=== (case comparison)
Ruby uses :=== in case/when constructs. The following code snippets are logically identical:

case foo
  when bar;  p 'do something'
end

if bar === foo
  p 'do something'
end

eql? (Hash-key comparison)
Ruby uses :eql? (in combination with the method hash) to compare Hash-keys. In most classes :eql? is identical with :==.
Knowledge about :eql? is only important, when you want to create your own special classes:

class Equ
  attr_accessor :val
  alias_method  :initialize, :val=
  def hash()           self.val % 2             end
  def eql?(other)      self.hash == other.hash  end
end

h = {Equ.new(3) => 3,  Equ.new(8) => 8,  Equ.new(15) => 15}    #3 entries, but 2 are :eql?
h.size            # => 2
h[Equ.new(27)]    # => 15

Note: The commonly used Ruby-class Set also relies on Hash-key-comparison.

equal? (object identity comparison)
Ruby uses :equal? to check if two objects are identical. This method (of class BasicObject) is not supposed to be overwritten.

obj = obj2 = 'a'
obj.equal? obj2       # => true
obj.equal? obj.dup    # => false

Maven skip tests

I can give you an example which results with the same problem, but it may not give you an answer to your question. (Additionally, in this example, I'm using my Maven 3 knowledge, which may not apply for Maven 2.)

In a multi-module maven project (contains modules A and B, where B depends on A), you can add also a test dependency on A from B.

This dependency may look as follows:

<dependency>
     <groupId>com.foo</groupId>
     <artifactId>A</artifactId>
     <type>test-jar</type> <!-- I'm not sure if there is such a thing in Maven 2, but there is definitely a way to achieve such dependency in Maven 2. -->
     <scope>test</scope>
</dependency>

(for more information refer to https://maven.apache.org/guides/mini/guide-attached-tests.html)
Note that the project A produces secondary artifact with a classifier tests where the test classes and test resources are located.

If you build your project with -Dmaven.test.skip=true, you will get a dependency resolution error as long as the test artifact wasn't found in your local repo or external repositories. The reason is that the tests classes were neither compiled nor the tests artifact was produced.
However, if you run your build with -DskipTests your tests artifact will be produced (though the tests won't run) and the dependency will be resolved.

KnockoutJs v2.3.0 : Error You cannot apply bindings multiple times to the same element

You just have to remove the bindings before you use 'applyBindings' again.

ko.cleanNode($element[0]);

should do the trick. HTH.

Check whether a string is not null and not empty

str != null && str.length() != 0

alternatively

str != null && !str.equals("")

str != null && !"".equals(str)

Note: The second check (first and second alternatives) assumes str is not null. It's ok only because the first check is doing that (and Java doesn't does the second check if the first is false)!

IMPORTANT: DON'T use == for string equality. == checks the pointer is equal, not the value. Two strings can be in different memory addresses (two instances) but have the same value!

Raw_Input() Is Not Defined

For Python 3.x, use input(). For Python 2.x, use raw_input(). Don't forget you can add a prompt string in your input() call to create one less print statement. input("GUESS THAT NUMBER!").

How to insert a picture into Excel at a specified cell position with VBA

I tested both @SWa and @Teamothy solution. I did not find the Pictures.Insert Method in the Microsoft Documentations and feared some compatibility issues. So I guess, the older Shapes.AddPicture Method should work on all versions. But it is slow!

On Error Resume Next
'
' first and faster method (in Office 2016)
'
    With ws.Pictures.Insert(Filename:=imageFileName, LinkToFile:=msoTrue, SaveWithDocument:=msoTrue)
        With .ShapeRange
            .LockAspectRatio = msoTrue
            .Width = destRange.Width
            .height = destRange.height '222
        End With
        .Left = destRange.Left
        .Top = destRange.Top
        .Placement = 1
        .PrintObject = True
        .Name = imageName
    End With
'
' second but slower method (in Office 2016)
'

If Err.Number <> 0 Then
    Err.Clear
    Dim myPic As Shape
    Set myPic = ws.Shapes.AddPicture(Filename:=imageFileName, _
            LinkToFile:=msoFalse, SaveWithDocument:=msoTrue, _
            Left:=destRange.Left, Top:=destRange.Top, Width:=-1, height:=destRange.height)

    With myPic.OLEFormat.Object.ShapeRange
        .LockAspectRatio = msoTrue
        .Width = destRange.Width
        .height = destRange.height '222
    End With
End If

Protect image download

There is no way to protect image downloading. This is because the image has to be downloaded by the browser for it to be seen by the user. There are tricks (like the transparent background you specified) to restrict certain operations like image right click and saving to browser cache folder, but there isn't a way for truly protecting the images.

What is the difference between an annotated and unannotated tag?

Push annotated tags, keep lightweight local

man git-tag says:

Annotated tags are meant for release while lightweight tags are meant for private or temporary object labels.

And certain behaviors do differentiate between them in ways that this recommendation is useful e.g.:

annotated tags can contain a message, creator, and date different than the commit they point to. So you could use them to describe a release without making a release commit.

Lightweight tags don't have that extra information, and don't need it, since you are only going to use it yourself to develop.
git push --follow-tags will only push annotated tags
git describe without command line options only sees annotated tags

Internals differences

both lightweight and annotated tags are a file under .git/refs/tags that contains a SHA-1
for lightweight tags, the SHA-1 points directly to a commit:
```
git tag light
cat .git/refs/tags/light
```
prints the same as the HEAD's SHA-1.

So no wonder they cannot contain any other metadata.
annotated tags point to a tag object in the object database.
```
git tag -as -m msg annot
cat .git/refs/tags/annot
```
contains the SHA of the annotated tag object:
```
c1d7720e99f9dd1d1c8aee625fd6ce09b3a81fef
```
and then we can get its content with:
```
git cat-file -p c1d7720e99f9dd1d1c8aee625fd6ce09b3a81fef
```
sample output:
```
object 4284c41353e51a07e4ed4192ad2e9eaada9c059f
type commit
tag annot
tagger Ciro Santilli <[email protected]> 1411478848 +0200

msg
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)

<YOUR PGP SIGNATURE>
-----END PGP SIGNAT
```
And this is how it contains extra metadata. As we can see from the output, the metadata fields are:
- the object it points to
- the type of object it points to. Yes, tag objects can point to any other type of object like blobs, not just commits.
- the name of the tag
- tagger identity and timestamp
- message. Note how the PGP signature is just appended to the message
A more detailed analysis of the format is present at: What is the format of a git tag object and how to calculate its SHA?

Bonuses

Determine if a tag is annotated:
```
git cat-file -t tag
```
Outputs
- commit for lightweight, since there is no tag object, it points directly to the commit
- tag for annotated, since there is a tag object in that case
List only lightweight tags: How can I list all lightweight tags?

Bootstrap-select - how to fire event on change

Simplest solution would be -

$('.selectpicker').trigger('change');

CSS: how to add white space before element's content?

You can use the unicode of a non breaking space :

p:before { content: "\00a0 "; }

See JSfiddle demo

[style improved by @Jason Sperske]

How do change the color of the text of an <option> within a <select>?

Suresh, you don't need use anything in your codes. What you need is just something like this:

_x000D_

.others {_x000D_
    color:black_x000D_
}

_x000D_

<select id="select">_x000D_
    <option style="color:gray" value="null">select one option</option>_x000D_
    <option value="1" class="others">one</option>_x000D_
    <option value="2" class="others">two</option>_x000D_
</select>

_x000D_

But as you can see, because your first item in options is the first thing that your select control shows, you can not see its assigned color. While if you open the select list and see the opened items, you will see you could assign a gray color to the first option. So you need something else in jQuery.

$(document).ready(function() {
   $('#select').css('color','gray');
   $('#select').change(function() {
      var current = $('#select').val();
      if (current != 'null') {
          $('#select').css('color','black');
      } else {
          $('#select').css('color','gray');
      }
   }); 
});

This is my code in jsFiddle.

Django Rest Framework -- no module named rest_framework

Install the missing module separately using pip installer

pip3 install djangorestframework-jsonapi

This worked for me.

How to print in C

try this:

printf("%d", addNumber(a,b))

Here's the documentation for printf.

Rounding a double value to x number of decimal places in swift

How do I round this down to, say, 1.543 when I print totalWorkTimeInHours?

To round totalWorkTimeInHours to 3 digits for printing, use the String constructor which takes a format string:

print(String(format: "%.3f", totalWorkTimeInHours))

how to resolve DTS_E_OLEDBERROR. in ssis

If it is related to the SSIS Package check may be possible that your source db contains few null rows. After removing them this issue will not appear any more.

Inline elements shifting when made bold on hover

_x000D_

ul {_x000D_
  list-style-marker: none;_x000D_
  padding: 0;_x000D_
}_x000D_
_x000D_
li {_x000D_
  display: inline-block;_x000D_
}_x000D_
_x000D_
li + li {_x000D_
  margin-left: 1em;_x000D_
}_x000D_
_x000D_
a {_x000D_
  display: block;_x000D_
  position: relative;_x000D_
  text-align: center;_x000D_
}_x000D_
_x000D_
a:before, a:after {_x000D_
  content: attr(aria-label);_x000D_
  text-decoration: inherit;_x000D_
}_x000D_
_x000D_
a:before {_x000D_
  font-weight: bold;_x000D_
  visibility: hidden;_x000D_
}_x000D_
_x000D_
a:after {_x000D_
  position: absolute;_x000D_
  left: 0;_x000D_
  top: 0;_x000D_
  right: 0;_x000D_
  bottom: 0;_x000D_
}_x000D_
_x000D_
a:hover:before {_x000D_
  visibility: visible;_x000D_
}_x000D_
_x000D_
a:hover:after {_x000D_
  display: none;_x000D_
}

_x000D_

<ul>_x000D_
  <li>_x000D_
    <a href="" aria-label="Long-long-long"></a>_x000D_
  </li><li>_x000D_
    <a href="" aria-label="or"></a>_x000D_
  </li><li>_x000D_
    <a href="" aria-label="Short"></a>_x000D_
  </li><li>_x000D_
    <a href="" aria-label="Links"></a>_x000D_
  </li><li>_x000D_
    <a href="" aria-label="Here"></a>_x000D_
  </li>_x000D_
</ul>

_x000D_

Python memory usage of numpy arrays

The field nbytes will give you the size in bytes of all the elements of the array in a numpy.array:

size_in_bytes = my_numpy_array.nbytes

Notice that this does not measures "non-element attributes of the array object" so the actual size in bytes can be a few bytes larger than this.

Returning from a void function

The first way is "more correct", what intention could there be to express? If the code ends, it ends. That's pretty clear, in my opinion.

I don't understand what could possibly be confusing and need clarification. If there's no looping construct being used, then what could possibly happen other than that the function stops executing?

I would be severly annoyed by such a pointless extra return statement at the end of a void function, since it clearly serves no purpose and just makes me feel the original programmer said "I was confused about this, and now you can be too!" which is not very nice.

How can I regenerate ios folder in React Native project?

As @Alok mentioned in the comments, you can do react-native eject to generate the ios and android folders. But you will need an app.json in your project first.

{"name": "example", "displayName": "Example"}

Simple Android RecyclerView example

To get started , just to view something in Recycler view

recycler view adapter can be something like this.

class CustomAdapter: RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
    var data =  listOf<String>()
        set(value) {
            field = value
            notifyDataSetChanged()
        }
    override fun getItemCount() =data.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.txt.text= data[position]
    }
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(
            LayoutInflater.from(parent.context).inflate(R.layout.item_view, parent, false)
        )
    }


    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
        val txt: TextView = itemView.findViewById(R.id.item_text_view)
    }
}

and to attach the adapter to the recycler view and to attach data to adapter

val view = findViewById<RecyclerView>(R.id.recycler_view)                                              
val adapter = CustomAdapter()                                                                          
val data = listOf("text1", "text2", "text3")
adapter.data = data                                                                             
view.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)
view.adapter = adapter

Where are include files stored - Ubuntu Linux, GCC

Karl answered your search-path question, but as far as the "source of the files" goes, one thing to be aware of is that if you install the libfoo package and want to do some development with it (i.e., use its headers), you will also need to install libfoo-dev. The standard library header files are already in /usr/include, as you saw.

Note that some libraries with a lot of headers will install them to a subdirectory, e.g., /usr/include/openssl. To include one of those, just provide the path without the /usr/include part, for example:

#include <openssl/aes.h>

Why are there no ++ and --? operators in Python?

Because, in Python, integers are immutable (int's += actually returns a different object).

Also, with ++/-- you need to worry about pre- versus post- increment/decrement, and it takes only one more keystroke to write x+=1. In other words, it avoids potential confusion at the expense of very little gain.

SQL query to select dates between two dates

There are a lot of bad answers and habits in this thread, when it comes to selecting based on a date range where the records might have non-zero time values - including the second highest answer at time of writing.

Never use code like this: Date between '2011/02/25' and '2011/02/27 23:59:59.999'

Or this: Date >= '2011/02/25' and Date <= '2011/02/27 23:59:59.999'

To see why, try it yourself:

DECLARE @DatetimeValues TABLE
    (MyDatetime datetime);
INSERT INTO @DatetimeValues VALUES
    ('2011-02-27T23:59:59.997')
    ,('2011-02-28T00:00:00');

SELECT MyDatetime
FROM @DatetimeValues
WHERE MyDatetime BETWEEN '2020-01-01T00:00:00' AND '2020-01-01T23:59:59.999';

SELECT MyDatetime
FROM @DatetimeValues
WHERE MyDatetime >= '2011-02-25T00:00:00' AND MyDatetime <= '2011-02-27T23:59:59.999';

In both cases, you'll get both rows back. Assuming the date values you're looking at are in the old datetime type, a date literal with a millisecond value of 999 used in a comparison with those dates will be rounded to millisecond 000 of the next second, as datetime isn't precise to the nearest millisecond. You can have 997 or 000, but nothing in between.

You could use the millisecond value of 997, and that would work - assuming you only ever need to work with datetime values, and not datetime2 values, as these can be far more precise. In that scenario, you would then miss records with a time value 23:59:59.99872, for example. The code originally suggested would also miss records with a time value of 23:59:59.9995, for example.

Far better is the other solution offered in the same answer - Date >= '2011/02/25' and Date < '2011/02/28'. Here, it doesn't matter whether you're looking at datetime or datetime2 columns, this will work regardless.

The other key point I'd like to raise is date and time literals. '2011/02/25' is not a good idea - depending on the settings of the system you're working in this could throw an error, as there's no 25th month. Use a literal format that works for all locality and language settings, e.g. '2011-02-25T00:00:00'.

Is there any way to call a function periodically in JavaScript?

Please note that setInterval() is often not the best solution for periodic execution - It really depends on what javascript you're actually calling periodically.

eg. If you use setInterval() with a period of 1000ms and in the periodic function you make an ajax call that occasionally takes 2 seconds to return you will be making another ajax call before the first response gets back. This is usually undesirable.

Many libraries have periodic methods that protect against the pitfalls of using setInterval naively such as the Prototype example given by Nelson.

To achieve more robust periodic execution with a function that has a jQuery ajax call in it, consider something like this:

function myPeriodicMethod() {
  $.ajax({
    url: ..., 
    success: function(data) {
      ...
    },
    complete: function() {
      // schedule the next request *only* when the current one is complete:
      setTimeout(myPeriodicMethod, 1000);
    }
  });
}

// schedule the first invocation:
setTimeout(myPeriodicMethod, 1000);

Another approach is to use setTimeout but track elapsed time in a variable and then set the timeout delay on each invocation dynamically to execute a function as close to the desired interval as possible but never faster than you can get responses back.

Python AttributeError: 'module' object has no attribute 'Serial'

If you are helpless like me, try this:

List all Sub-Modules of "Serial" (or whatever package you are having trouble with) with the method described here: List all the modules that are part of a python package

In my case, the problems solved one after the other.

...looks like a bug to me...

How to capture and save an image using custom camera in Android?

please see below answer.

Custom_CameraActivity.java

public class Custom_CameraActivity extends Activity {
    private Camera mCamera;
    private CameraPreview mCameraPreview;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mCamera = getCameraInstance();
        mCameraPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mCameraPreview);

        Button captureButton = (Button) findViewById(R.id.button_capture);
        captureButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mCamera.takePicture(null, null, mPicture);
            }
        });
    }

    /**
     * Helper method to access the camera returns null if it cannot get the
     * camera or does not exist
     * 
     * @return
     */
    private Camera getCameraInstance() {
        Camera camera = null;
        try {
            camera = Camera.open();
        } catch (Exception e) {
            // cannot get camera or does not exist
        }
        return camera;
    }

    PictureCallback mPicture = new PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            File pictureFile = getOutputMediaFile();
            if (pictureFile == null) {
                return;
            }
            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();
            } catch (FileNotFoundException e) {

            } catch (IOException e) {
            }
        }
    };

    private static File getOutputMediaFile() {
        File mediaStorageDir = new File(
                Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
                "MyCameraApp");
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.d("MyCameraApp", "failed to create directory");
                return null;
            }
        }
        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
                .format(new Date());
        File mediaFile;
        mediaFile = new File(mediaStorageDir.getPath() + File.separator
                + "IMG_" + timeStamp + ".jpg");

        return mediaFile;
    }
}

CameraPreview.java

public class CameraPreview extends SurfaceView implements
        SurfaceHolder.Callback {
    private SurfaceHolder mSurfaceHolder;
    private Camera mCamera;

    // Constructor that obtains context and camera
    @SuppressWarnings("deprecation")
    public CameraPreview(Context context, Camera camera) {
        super(context);
        this.mCamera = camera;
        this.mSurfaceHolder = this.getHolder();
        this.mSurfaceHolder.addCallback(this);
        this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        try {
            mCamera.setPreviewDisplay(surfaceHolder);
            mCamera.startPreview();
        } catch (IOException e) {
            // left blank for now
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
        mCamera.stopPreview();
        mCamera.release();
    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
            int width, int height) {
        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(surfaceHolder);
            mCamera.startPreview();
        } catch (Exception e) {
            // intentionally left blank for a test
        }
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal" >

    <FrameLayout
        android:id="@+id/camera_preview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1" />

    <Button
        android:id="@+id/button_capture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="Capture" />

</LinearLayout>

Add Below Lines to your androidmanifest.xml file

<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Must declare the scalar variable

Just FYI, I know this is an old post, but depending on the database COLLATION settings you can get this error on a statement like this,

SET @sql = @Sql + ' WHERE RowNum BETWEEN @RowFrom AND @RowTo;';

if for example you typo the S in the

SET @sql = @***S***ql

sorry to spin off the answers already posted here, but this is an actual instance of the error reported.

Note also that the error will not display the capital S in the message, I am not sure why, but I think it is because the

Set @sql =

is on the left of the equal sign.

How to convert .crt to .pem

You can do this conversion with the OpenSSL library

http://www.openssl.org/

Windows binaries can be found here:

http://www.slproweb.com/products/Win32OpenSSL.html

Once you have the library installed, the command you need to issue is:

openssl x509 -in mycert.crt -out mycert.pem -outform PEM

Exclude all transitive dependencies of a single dependency

There is a workaround for this, if you set the scope of a dependency to runtime, transitive dependencies will be excluded. Though be aware this means you need to add in additional processing if you want to package the runtime dependency.

To include the runtime dependency in any packaging, you can use the maven-dependency-plugin's copy goal for a specific artifact.

How to trim leading and trailing white spaces of a string?

For trimming your string, Go's "strings" package have TrimSpace(), Trim() function that trims leading and trailing spaces.

Check the documentation for more information.

How to execute an SSIS package from .NET?

So there is another way you can actually fire it from any language. The best way I think, you can just create a batch file which will call your .dtsx package.

Next you call the batch file from any language. As in windows platform, you can run batch file from anywhere, I think this will be the most generic approach for your purpose. No code dependencies.

Below is a blog for more details..

https://www.mssqltips.com/sqlservertutorial/218/command-line-tool-to-execute-ssis-packages/

Happy coding.. :)

Thanks, Ayan

How to print a specific row of a pandas DataFrame?

Use ix operator:

print df.ix[159220]

Eclipse: Error ".. overlaps the location of another project.." when trying to create new project

Eclipse is erroring because if you try and create a project on a directory that exists, Eclipse doesn't know if it's an actual project or not - so it errors, saving you from losing work!

So you have two solutions:

Move the folder counter_src somewhere else, then create the project (which will create the directory), then import the source files back into the newly created counter_src.
Right-click on the project explorer and import an existing project, select C:\Users\Martin\Java\Counter\ as your root directory. If Eclipse sees a project, you will be able to import it.

Java ArrayList Index

You have ArrayList all wrong,

You can't have an integer array and assign a string value.
You cannot do a add() method in an array

Rather do this:

List<String> alist = new ArrayList<String>();
alist.add("apple");
alist.add("banana");
alist.add("orange");

String value = alist.get(1); //returns the 2nd item from list, in this case "banana"

Indexing is counted from 0 to N-1 where N is size() of list.

SQL Server check case-sensitivity?

SQL Server is not case sensitive. SELECT * FROM SomeTable is the same as SeLeCT * frOM soMetaBLe.

Add a new item to recyclerview programmatically?

if you are adding multiple items to the list use this:

mAdapter.notifyItemRangeInserted(startPosition, itemcount);

This notify any registered observers that the currently reflected itemCount items starting at positionStart have been newly inserted. The item previously located at positionStart and beyond can now be found starting at position positinStart+itemCount

existing item in the dataset still considered up to date.

Why does the jquery change event not trigger when I set the value of a select using val()?

Adding this piece of code after the val() seems to work:

$(":input#single").trigger('change');

Flattening a shallow list in Python

There seems to be a confusion with operator.add! When you add two lists together, the correct term for that is concat, not add. operator.concat is what you need to use.

If you're thinking functional, it is as easy as this::

>>> list2d = ((1,2,3),(4,5,6), (7,), (8,9))
>>> reduce(operator.concat, list2d)
(1, 2, 3, 4, 5, 6, 7, 8, 9)

You see reduce respects the sequence type, so when you supply a tuple, you get back a tuple. let's try with a list::

>>> list2d = [[1,2,3],[4,5,6], [7], [8,9]]
>>> reduce(operator.concat, list2d)
[1, 2, 3, 4, 5, 6, 7, 8, 9]

Aha, you get back a list.

How about performance::

>>> list2d = [[1,2,3],[4,5,6], [7], [8,9]]
>>> %timeit list(itertools.chain.from_iterable(list2d))
1000000 loops, best of 3: 1.36 µs per loop

from_iterable is pretty fast! But it's no comparison to reduce with concat.

>>> list2d = ((1,2,3),(4,5,6), (7,), (8,9))
>>> %timeit reduce(operator.concat, list2d)
1000000 loops, best of 3: 492 ns per loop

How to make a round button?

Create a drawable/button_states.xml file containing:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="false"> 
        <shape android:shape="rectangle">
        <corners android:radius="1000dp" />
        <solid android:color="#41ba7a" />
        <stroke
            android:width="2dip"
            android:color="#03ae3c" />
        <padding
            android:bottom="4dp"
            android:left="4dp"
            android:right="4dp"
            android:top="4dp" />
        </shape>
    </item>
    <item android:state_pressed="true"> 
        <shape android:shape="rectangle">
        <corners android:radius="1000dp" />
        <solid android:color="#3AA76D" />
        <stroke
            android:width="2dip"
            android:color="#03ae3c" />
        <padding
            android:bottom="4dp"
            android:left="4dp"
            android:right="4dp"
            android:top="4dp" />
        </shape>
    </item>
</selector>

Use it in button tag in any layout file

<Button
    android:layout_width="220dp"
    android:layout_height="220dp"
    android:background="@drawable/button_states"
    android:text="@string/btn_scan_qr"
    android:id="@+id/btn_scan_qr"
    android:textSize="15dp"
/>

Put byte array to JSON and vice versa

what about simply this:

byte[] args2 = getByteArry();
String byteStr = new String(args2);

Return None if Dictionary key is not available

Use dict.get

Returns the value for key if key is in the dictionary, else default. If default is not given, it defaults to None, so that this method never raises a KeyError.

iFrame onload JavaScript event

Use the iFrame's .onload function of JavaScript:

<iframe id="my_iframe" src="http://www.test.tld/">
    <script type="text/javascript">
        document.getElementById('my_iframe').onload = function() {
            __doPostBack('ctl00$ctl00$bLogout','');
        }
    </script>
    <!--OTHER STUFF-->
</iframe>

Simple UDP example to send and receive data from same socket

(I presume you are aware that using UDP(User Datagram Protocol) does not guarantee delivery, checks for duplicates and congestion control and will just answer your question).

In your server this line:

var data = udpServer.Receive(ref groupEP);

re-assigns groupEP from what you had to a the address you receive something on.

This line:

udpServer.Send(new byte[] { 1 }, 1);

Will not work since you have not specified who to send the data to. (It works on your client because you called connect which means send will always be sent to the end point you connected to, of course we don't want that on the server as we could have many clients). I would:

UdpClient udpServer = new UdpClient(UDP_LISTEN_PORT);

while (true)
{
    var remoteEP = new IPEndPoint(IPAddress.Any, 11000);
    var data = udpServer.Receive(ref remoteEP);
    udpServer.Send(new byte[] { 1 }, 1, remoteEP); // if data is received reply letting the client know that we got his data          
}

Also if you have server and client on the same machine you should have them on different ports.

Java 8 optional: ifPresent return object orElseThrow exception

Two options here:

Replace ifPresent with map and use Function instead of Consumer

private String getStringIfObjectIsPresent(Optional<Object> object) {
    return object
            .map(obj -> {
                String result = "result";
                //some logic with result and return it
                return result;
            })
            .orElseThrow(MyCustomException::new);
}

Use isPresent:

private String getStringIfObjectIsPresent(Optional<Object> object) {
    if (object.isPresent()) {
        String result = "result";
        //some logic with result and return it
        return result;
    } else {
        throw new MyCustomException();
    }
}

UIButton Image + Text IOS

Xcode-9 and Xcode-10 Apple done few changes regarding Edge Inset now, you can change it under size-inspector.

Please follow below steps:

Step-1: Input text and select image which you want to show:

Step-2: Select button control as per your requirement as shown in below image:

Step-3: Now go-to size inspector and add value as per your requirement:

What are "res" and "req" parameters in Express functions?

I noticed one error in Dave Ward's answer (perhaps a recent change?): The query string paramaters are in request.query, not request.params. (See https://stackoverflow.com/a/6913287/166530 )

request.params by default is filled with the value of any "component matches" in routes, i.e.

app.get('/user/:id', function(request, response){
  response.send('user ' + request.params.id);
});

and, if you have configured express to use its bodyparser (app.use(express.bodyParser());) also with POST'ed formdata. (See How to retrieve POST query parameters? )

How do I open an .exe from another C++ .exe?

Provide the full path of the file openfile.exe and remember not to put forward slash / in the path such as c:/users/username/etc.... instead of that use c:\\Users\\username\etc (for windows)

May be this will help you.

How can I close a browser window without receiving the "Do you want to close this window" prompt?

window.open('', '_self', ''); window.close();

This works for me.

How to upload files to server using Putty (ssh)

You need an scp client. Putty is not one. You can use WinSCP or PSCP. Both are free software.

Asynchronously load images with jQuery

No need for ajax. You can create a new image element, set its source attribute and place it somewhere in the document once it has finished loading:

var img = $("<img />").attr('src', 'http://somedomain.com/image.jpg')
    .on('load', function() {
        if (!this.complete || typeof this.naturalWidth == "undefined" || this.naturalWidth == 0) {
            alert('broken image!');
        } else {
            $("#something").append(img);
        }
    });

Append data frames together in a for loop

Don't do it inside the loop. Make a list, then combine them outside the loop.

datalist = list()

for (i in 1:5) {
    # ... make some data
    dat <- data.frame(x = rnorm(10), y = runif(10))
    dat$i <- i  # maybe you want to keep track of which iteration produced it?
    datalist[[i]] <- dat # add it to your list
}

big_data = do.call(rbind, datalist)
# or big_data <- dplyr::bind_rows(datalist)
# or big_data <- data.table::rbindlist(datalist)

This is a much more R-like way to do things. It can also be substantially faster, especially if you use dplyr::bind_rows or data.table::rbindlist for the final combining of data frames.

Download a file from NodeJS Server using Express

Update

Express has a helper for this to make life easier.

app.get('/download', function(req, res){
  const file = `${__dirname}/upload-folder/dramaticpenguin.MOV`;
  res.download(file); // Set disposition and send it.
});

Old Answer

As far as your browser is concerned, the file's name is just 'download', so you need to give it more info by using another HTTP header.

res.setHeader('Content-disposition', 'attachment; filename=dramaticpenguin.MOV');

You may also want to send a mime-type such as this:

res.setHeader('Content-type', 'video/quicktime');

If you want something more in-depth, here ya go.

var path = require('path');
var mime = require('mime');
var fs = require('fs');

app.get('/download', function(req, res){

  var file = __dirname + '/upload-folder/dramaticpenguin.MOV';

  var filename = path.basename(file);
  var mimetype = mime.lookup(file);

  res.setHeader('Content-disposition', 'attachment; filename=' + filename);
  res.setHeader('Content-type', mimetype);

  var filestream = fs.createReadStream(file);
  filestream.pipe(res);
});

You can set the header value to whatever you like. In this case, I am using a mime-type library - node-mime, to check what the mime-type of the file is.

Another important thing to note here is that I have changed your code to use a readStream. This is a much better way to do things because using any method with 'Sync' in the name is frowned upon because node is meant to be asynchronous.

Using helpers in model: how do I include helper dependencies?

Just change the first line as follows :

include ActionView::Helpers

that will make it works.

UPDATE: For Rails 3 use:

ActionController::Base.helpers.sanitize(str)

Credit goes to lornc's answer

In NetBeans how do I change the Default JDK?

If I remember correctly, you'll need to set the netbeans_jdkhome property in your netbeans config file. Should be in your etc/netbeans.conf file.

CSS3 selector :first-of-type with class name?

Simply :first works for me, why isn't this mentioned yet?

How to calculate rolling / moving average using NumPy / SciPy?

I actually wanted a slightly different behavior than the accepted answer. I was building a moving average feature extractor for an sklearn pipeline, so I required that the output of the moving average have the same dimension as the input. What I want is for the moving average to assume the series stays constant, ie a moving average of [1,2,3,4,5] with window 2 would give [1.5,2.5,3.5,4.5,5.0].

For column vectors (my use case) we get

def moving_average_col(X, n):
  z2 = np.cumsum(np.pad(X, ((n,0),(0,0)), 'constant', constant_values=0), axis=0)
  z1 = np.cumsum(np.pad(X, ((0,n),(0,0)), 'constant', constant_values=X[-1]), axis=0)
  return (z1-z2)[(n-1):-1]/n

And for arrays

def moving_average_array(X, n):
  z2 = np.cumsum(np.pad(X, (n,0), 'constant', constant_values=0))
  z1 = np.cumsum(np.pad(X, (0,n), 'constant', constant_values=X[-1]))
  return (z1-z2)[(n-1):-1]/n

Of course, one doesn't have to assume constant values for the padding, but doing so should be adequate in most cases.

Add disabled attribute to input element using Javascript

If you're using jQuery then there are a few different ways to set the disabled attribute.

var $element = $(...);
    $element.prop('disabled', true);
    $element.attr('disabled', true); 

    // The following do not require jQuery
    $element.get(0).disabled = true;
    $element.get(0).setAttribute('disabled', true);
    $element[0].disabled = true;
    $element[0].setAttribute('disabled', true);

"The certificate chain was issued by an authority that is not trusted" when connecting DB in VM Role from Azure website

If you're seeing this error message when attempting to connect using SSMS, add TrustServerCertificate=True to the Additional Connection Parameters.

Plotting images side by side using matplotlib

If the images are in an array and you want to iterate through each element and print it, you can write the code as follows:

plt.figure(figsize=(10,10)) # specifying the overall grid size

for i in range(25):
    plt.subplot(5,5,i+1)    # the number of images in the grid is 5*5 (25)
    plt.imshow(the_array[i])

plt.show()

Also note that I used subplot and not subplots. They're both different

"Templates can be used only with field access, property access, single-dimension array index, or single-parameter custom indexer expressions" error

I had the same problem with something like

@foreach (var item in Model)
{
    @Html.DisplayFor(m => !item.IsIdle, "BoolIcon")
}

I solved this just by doing

@foreach (var item in Model)
{
    var active = !item.IsIdle;
    @Html.DisplayFor(m => active , "BoolIcon")
}

When you know the trick, it's simple.

The difference is that, in the first case, I passed a method as a parameter whereas in the second case, it's an expression.

Split comma-separated values

.NET 2.0 does not use lambda expressions. You need to compile to .NET 3.0 to use them.

How to go from Blob to ArrayBuffer

You can use FileReader to read the Blob as an ArrayBuffer.

Here's a short example:

var arrayBuffer;
var fileReader = new FileReader();
fileReader.onload = function(event) {
    arrayBuffer = event.target.result;
};
fileReader.readAsArrayBuffer(blob);

Here's a longer example:

// ArrayBuffer -> Blob
var uint8Array  = new Uint8Array([1, 2, 3]);
var arrayBuffer = uint8Array.buffer;
var blob        = new Blob([arrayBuffer]);

// Blob -> ArrayBuffer
var uint8ArrayNew  = null;
var arrayBufferNew = null;
var fileReader     = new FileReader();
fileReader.onload  = function(event) {
    arrayBufferNew = event.target.result;
    uint8ArrayNew  = new Uint8Array(arrayBufferNew);

    // warn if read values are not the same as the original values
    // arrayEqual from: http://stackoverflow.com/questions/3115982/how-to-check-javascript-array-equals
    function arrayEqual(a, b) { return !(a<b || b<a); };
    if (arrayBufferNew.byteLength !== arrayBuffer.byteLength) // should be 3
        console.warn("ArrayBuffer byteLength does not match");
    if (arrayEqual(uint8ArrayNew, uint8Array) !== true) // should be [1,2,3]
        console.warn("Uint8Array does not match");
};
fileReader.readAsArrayBuffer(blob);
fileReader.result; // also accessible this way once the blob has been read

This was tested out in the console of Chrome 27—69, Firefox 20—60, and Safari 6—11.

Here's also a live demonstration which you can play with: https://jsfiddle.net/potatosalad/FbaM6/

Update 2018-06-23: Thanks to Klaus Klein for the tip about event.target.result versus this.result

Reference:

How to use Visual Studio Code as Default Editor for Git

Just want to add these back slashes to previous answers, I am on Windows 10 CMD, and it doesn't work without back slashes before the spaces.

git config --global core.editor "C:\\Users\\your_user_name\\AppData\\Local\\Programs\\Microsoft\ VS\ Code\\Code.exe"

Http Get using Android HttpURLConnection

Try getting the input stream from this you can then get the text data as so:-

    URL url;
    HttpURLConnection urlConnection = null;
    try {
        url = new URL("http://www.mysite.se/index.asp?data=99");

        urlConnection = (HttpURLConnection) url
                .openConnection();

        InputStream in = urlConnection.getInputStream();

        InputStreamReader isw = new InputStreamReader(in);

        int data = isw.read();
        while (data != -1) {
            char current = (char) data;
            data = isw.read();
            System.out.print(current);
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (urlConnection != null) {
            urlConnection.disconnect();
        }    
    }

You can probably use other inputstream readers such as buffered reader also.

The problem is that when you open the connection - it does not 'pull' any data.

Open S3 object as a string with Boto3

read will return bytes. At least for Python 3, if you want to return a string, you have to decode using the right encoding:

import boto3

s3 = boto3.resource('s3')

obj = s3.Object(bucket, key)
obj.get()['Body'].read().decode('utf-8')

WPF - add static items to a combo box

<ComboBox Text="Something">
            <ComboBoxItem Content="Item1"></ComboBoxItem >
            <ComboBoxItem Content="Item2"></ComboBoxItem >
            <ComboBoxItem Content="Item3"></ComboBoxItem >
</ComboBox>

Want to upgrade project from Angular v5 to Angular v6

simply run the following command:

ng update

note: this will not update globally.

Using pickle.dump - TypeError: must be str, not bytes

The output file needs to be opened in binary mode:

f = open('varstor.txt','w')

needs to be:

f = open('varstor.txt','wb')

How can I see the raw SQL queries Django is running?

For Django 2.2:

As most of the answers did not helped me much when using ./manage.py shell. Finally i found the answer. Hope this helps to someone.

To view all the queries:

from django.db import connection
connection.queries

To view query for a single query:

q=Query.objects.all()
q.query.__str__()

q.query just displaying the object for me. Using the __str__()(String representation) displayed the full query.

Retrieving Property name from lambda expression

I found another way you can do it was to have the source and property strongly typed and explicitly infer the input for the lambda. Not sure if that is correct terminology but here is the result.

public static RouteValueDictionary GetInfo<T,P>(this HtmlHelper html, Expression<Func<T, P>> action) where T : class
{
    var expression = (MemberExpression)action.Body;
    string name = expression.Member.Name;

    return GetInfo(html, name);
}

And then call it like so.

GetInfo((User u) => u.UserId);

and voila it works.

How to convert integer to decimal in SQL Server query?

You can either cast Height as a decimal:

select cast(@height as decimal(10, 5))/10 as heightdecimal

or you place a decimal point in your value you are dividing by:

declare @height int
set @height = 1023

select @height/10.0 as heightdecimal

see sqlfiddle with an example

Decompile an APK, modify it and then recompile it

I know this question has been answered and I am not trying to give better answer here. I'll just share my experience in this topic.

Once I lost my code and I had the apk file only. I decompiled it using the tool below and it made my day.

These tools MUST be used in such situation, otherwise, it is unethical and even sometimes it is illegal, (stealing somebody else's effort). So please use it wisely.

Those are my favorite tools for doing that:

javadecompilers.com

and to get the apk from google play you can google it or check out those sites:

On the date of posting this answer I tested all the links and it worked perfect for me.

NOTE: Apk Decompiling is not effective in case of proguarded code. Because Proguard shrink and obfuscates the code and rename classes to nonsense names which make it fairly hard to understand the code.

Bonus:

Basic tutorial of Using Proguard:

How do I capture all of my compiler's output to a file?

The output went to stderr. Use 2> to capture that.

$make 2> file

How to check not in array element

if (in_array($id,$user_access_arr)==0)
{
    $this->Session->setFlash(__('Access Denied! You are not eligible to access this.'), 'flash_custom_success');
    return $this->redirect(array('controller'=>'Dashboard','action'=>'index'));
}

X close button only using css

As a pure CSS solution for the close or 'times' symbol you can use the ISO code with the content property. I often use this for :after or :before pseudo selectors.

The content code is \00d7.

Example

div:after{
  display: inline-block;
  content: "\00d7"; /* This will render the 'X' */
}

You can then style and position the pseudo selector in any way you want. Hope this helps someone :).

How to write a multidimensional array to a text file?

If you don't need a human-readable output, another option you could try is to save the array as a MATLAB .mat file, which is a structured array. I despise MATLAB, but the fact that I can both read and write a .mat in very few lines is convenient.

Unlike Joe Kington's answer, the benefit of this is that you don't need to know the original shape of the data in the .mat file, i.e. no need to reshape upon reading in. And, unlike using pickle, a .mat file can be read by MATLAB, and probably some other programs/languages as well.

Here is an example:

import numpy as np
import scipy.io

# Some test data
x = np.arange(200).reshape((4,5,10))

# Specify the filename of the .mat file
matfile = 'test_mat.mat'

# Write the array to the mat file. For this to work, the array must be the value
# corresponding to a key name of your choice in a dictionary
scipy.io.savemat(matfile, mdict={'out': x}, oned_as='row')

# For the above line, I specified the kwarg oned_as since python (2.7 with 
# numpy 1.6.1) throws a FutureWarning.  Here, this isn't really necessary 
# since oned_as is a kwarg for dealing with 1-D arrays.

# Now load in the data from the .mat that was just saved
matdata = scipy.io.loadmat(matfile)

# And just to check if the data is the same:
assert np.all(x == matdata['out'])

If you forget the key that the array is named in the .mat file, you can always do:

print matdata.keys()

And of course you can store many arrays using many more keys.

So yes – it won't be readable with your eyes, but only takes 2 lines to write and read the data, which I think is a fair trade-off.

Take a look at the docs for scipy.io.savemat and scipy.io.loadmat and also this tutorial page: scipy.io File IO Tutorial

The difference between Classes, Objects, and Instances

Any kind of data your computer stores and processes is in its most basic representation a row of bits. The way those bits are interpreted is done through data types. Data types can be primitive or complex. Primitive data types are - for instance - int or double. They have a specific length and a specific way of being interpreted. In the case of an integer, usually the first bit is used for the sign, the others are used for the value.

Complex data types can be combinations of primitive and other complex data types and are called "Class" in Java.

You can define the complex data type PeopleName consisting of two Strings called first and last name. Each String in Java is another complex data type. Strings in return are (probably) implemented using the primitive data type char for which Java knows how many bits they take to store and how to interpret them.

When you create an instance of a data type, you get an object and your computers reserves some memory for it and remembers its location and the name of that instance. An instance of PeopleName in memory will take up the space of the two String variables plus a bit more for bookkeeping. An integer takes up 32 bits in Java.

Complex data types can have methods assigned to them. Methods can perform actions on their arguments or on the instance of the data type you call this method from. If you have two instances of PeopleName called p1 and p2 and you call a method p1.getFirstName(), it usually returns the first name of the first person but not the second person's.

C - Convert an uppercase letter to lowercase

You can convert a character from lower case to upper case and vice-versa using bit manipulation as shown below:

#include<stdio.h>
int main(){
  char c;
  printf("Enter a character in uppercase\n");
  scanf("%c",&c);
  c|=' '; // perform or operation on c and ' '
  printf("The lower case of %c is \n",c);
  c&='_'; // perform 'and' operation with '_' to get upper case letter. 
  printf("Back to upper case %c\n",c);   
  return 0;
}

Swift addsubview and remove it

You have to use the viewWithTag function to find the view with the given tag.

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    let touch = touches.anyObject() as UITouch
    let point = touch.locationInView(self.view)

    if let viewWithTag = self.view.viewWithTag(100) {
        print("Tag 100")
        viewWithTag.removeFromSuperview()
    } else {
        print("tag not found")
    }
}

Getting an option text/value with JavaScript

You can use:

var option_user_selection = element.options[ element.selectedIndex ].text

Change bullets color of an HTML list without using span

Inline version, works for Outlook Desktop:

<ul style="list-style:square;">
  <li style="color:red;"><span style="color:black;">Lorem.</span></li>
  <li style="color:red;"><span style="color:black;">Lorem.</span></li>
</ul>

JSFiddle.

How to tell if a connection is dead in python

I translated the code sample in this blog post into Python: How to detect when the client closes the connection?, and it works well for me:

from ctypes import (
    CDLL, c_int, POINTER, Structure, c_void_p, c_size_t,
    c_short, c_ssize_t, c_char, ARRAY
)


__all__ = 'is_remote_alive',


class pollfd(Structure):
    _fields_ = (
        ('fd', c_int),
        ('events', c_short),
        ('revents', c_short),
    )


MSG_DONTWAIT = 0x40
MSG_PEEK = 0x02

EPOLLIN = 0x001
EPOLLPRI = 0x002
EPOLLRDNORM = 0x040

libc = CDLL(None)

recv = libc.recv
recv.restype = c_ssize_t
recv.argtypes = c_int, c_void_p, c_size_t, c_int

poll = libc.poll
poll.restype = c_int
poll.argtypes = POINTER(pollfd), c_int, c_int


class IsRemoteAlive:  # not needed, only for debugging
    def __init__(self, alive, msg):
        self.alive = alive
        self.msg = msg

    def __str__(self):
        return self.msg

    def __repr__(self):
        return 'IsRemoteClosed(%r,%r)' % (self.alive, self.msg)

    def __bool__(self):
        return self.alive


def is_remote_alive(fd):
    fileno = getattr(fd, 'fileno', None)
    if fileno is not None:
        if hasattr(fileno, '__call__'):
            fd = fileno()
        else:
            fd = fileno

    p = pollfd(fd=fd, events=EPOLLIN|EPOLLPRI|EPOLLRDNORM, revents=0)
    result = poll(p, 1, 0)
    if not result:
        return IsRemoteAlive(True, 'empty')

    buf = ARRAY(c_char, 1)()
    result = recv(fd, buf, len(buf), MSG_DONTWAIT|MSG_PEEK)
    if result > 0:
        return IsRemoteAlive(True, 'readable')
    elif result == 0:
        return IsRemoteAlive(False, 'closed')
    else:
        return IsRemoteAlive(False, 'errored')

Pygame Drawing a Rectangle

import pygame, sys
from pygame.locals import *

def main():
    pygame.init()

    DISPLAY=pygame.display.set_mode((500,400),0,32)

    WHITE=(255,255,255)
    BLUE=(0,0,255)

    DISPLAY.fill(WHITE)

    pygame.draw.rect(DISPLAY,BLUE,(200,150,100,50))

    while True:
        for event in pygame.event.get():
            if event.type==QUIT:
                pygame.quit()
                sys.exit()
        pygame.display.update()

main()

This creates a simple window 500 pixels by 400 pixels that is white. Within the window will be a blue rectangle. You need to use the pygame.draw.rect to go about this, and you add the DISPLAY constant to add it to the screen, the variable blue to make it blue (blue is a tuple that values which equate to blue in the RGB values and it's coordinates.

Look up pygame.org for more info

How can I add a line to a file in a shell script?

This doesn't use sed, but using >> will append to a file. For example:

echo 'one, two, three' >> testfile.csv

Edit: To prepend to a file, try something like this:

echo "text"|cat - yourfile > /tmp/out && mv /tmp/out yourfile

I found this through a quick Google search.

Excel VBA: Copying multiple sheets into new workbook

Rethink your approach. Why would you copy only part of the sheet? You are referring to a named range "WholePrintArea" which doesn't exist. Also you should never use activate, select, copy or paste in your script. These make the "script" vulnerable to user actions and other simultaneous executions. In worst case scenario data ends up in wrong hands.

How to plot a 2D FFT in Matlab?

Assuming that I is your input image and F is its Fourier Transform (i.e. F = fft2(I))

You can use this code:

F = fftshift(F); % Center FFT

F = abs(F); % Get the magnitude
F = log(F+1); % Use log, for perceptual scaling, and +1 since log(0) is undefined
F = mat2gray(F); % Use mat2gray to scale the image between 0 and 1

imshow(F,[]); % Display the result

jQuery add image inside of div tag

my 2 cents:

$('#theDiv').prepend($('<img>',{id:'theImg',src:'theImg.png'}))

How to clone an InputStream?

Below is the solution with Kotlin.

You can copy your InputStream into ByteArray

val inputStream = ...

val byteOutputStream = ByteArrayOutputStream()
inputStream.use { input ->
    byteOutputStream.use { output ->
        input.copyTo(output)
    }
}

val byteInputStream = ByteArrayInputStream(byteOutputStream.toByteArray())

If you need to read the byteInputStream multiple times, call byteInputStream.reset() before reading again.

https://code.luasoftware.com/tutorials/kotlin/how-to-clone-inputstream/

How can I parse a YAML file in Python

Example:

defaults.yaml

url: https://www.google.com

environment.py

from ruamel import yaml

data = yaml.safe_load(open('defaults.yaml'))
data['url']

Find row in datatable with specific id

You can try with method select

DataRow[] rows = table.Select("ID = 7");

if else statement in AngularJS templates

In the latest version of Angular (as of 1.1.5), they have included a conditional directive called ngIf. It is different from ngShow and ngHide in that the elements aren't hidden, but not included in the DOM at all. They are very useful for components which are costly to create but aren't used:

<div ng-if="video == video.large">
    <!-- code to render a large video block-->
</div>
<div ng-if="video != video.large">
    <!-- code to render the regular video block -->
</div>

How to reload / refresh model data from the server programmatically?

Before I show you how to reload / refresh model data from the server programmatically? I have to explain for you the concept of Data Binding. This is an extremely powerful concept that will truly revolutionize the way you develop. So may be you have to read about this concept from this link or this seconde link in order to unterstand how AngularjS work.

now I'll show you a sample example that exaplain how can you update your model from server.

HTML Code:

<div ng-controller="PersonListCtrl">
    <ul>
        <li ng-repeat="person in persons">
            Name: {{person.name}}, Age {{person.age}}
        </li>
    </ul>
   <button ng-click="updateData()">Refresh Data</button>
</div>

So our controller named: PersonListCtrl and our Model named: persons. go to your Controller js in order to develop the function named: updateData() that will be invoked when we are need to update and refresh our Model persons.

Javascript Code:

app.controller('adsController', function($log,$scope,...){

.....

$scope.updateData = function(){
$http.get('/persons').success(function(data) {
       $scope.persons = data;// Update Model-- Line X
     });
}

});

Now I explain for you how it work: when user click on button Refresh Data, the server will call to function updateData() and inside this function we will invoke our web service by the function $http.get() and when we have the result from our ws we will affect it to our model (Line X).Dice that affects the results for our model, our View of this list will be changed with new Data.

How do I zip two arrays in JavaScript?

Zip Arrays of same length:

Using Array.prototype.map()

_x000D_

const zip = (a, b) => a.map((k, i) => [k, b[i]]);

console.log(zip([1,2,3], ["a","b","c"]));
// [[1, "a"], [2, "b"], [3, "c"]]

_x000D_

Zip Arrays of different length:

Using Array.from()

_x000D_

const zip = (a, b) => Array.from(Array(Math.max(b.length, a.length)), (_, i) => [a[i], b[i]]);

console.log( zip([1,2,3], ["a","b","c","d"]) );
// [[1, "a"], [2, "b"], [3, "c"], [undefined, "d"]]

_x000D_

Using Array.prototype.fill() and Array.prototype.map()

_x000D_

const zip = (a, b) => Array(Math.max(b.length, a.length)).fill().map((_,i) => [a[i], b[i]]);

console.log(zip([1,2,3], ["a","b","c","d"]));
// [[1, "a"], [2, "b"], [3, "c"], [undefined, 'd']]

_x000D_

ValueError: unsupported pickle protocol: 3, python2 pickle can not load the file dumped by python 3 pickle?

You should write the pickled data with a lower protocol number in Python 3. Python 3 introduced a new protocol with the number 3 (and uses it as default), so switch back to a value of 2 which can be read by Python 2.

Check the protocolparameter in pickle.dump. Your resulting code will look like this.

pickle.dump(your_object, your_file, protocol=2)

There is no protocolparameter in pickle.load because pickle can determine the protocol from the file.

PostgreSQL: role is not permitted to log in

The role you have created is not allowed to log in. You have to give the role permission to log in.

One way to do this is to log in as the postgres user and update the role:

psql -U postgres

Once you are logged in, type:

ALTER ROLE "asunotest" WITH LOGIN;

Here's the documentation http://www.postgresql.org/docs/9.0/static/sql-alterrole.html

What is the role of the bias in neural networks?

Just to add my two cents.

A simpler way to understand what the bias is: it is somehow similar to the constant b of a linear function

y = ax + b

It allows you to move the line up and down to fit the prediction with the data better. Without b the line always goes through the origin (0, 0) and you may get a poorer fit.

Changing directory in Google colab (breaking out of the python interpreter)

!pwd
import os
os.chdir('/content/drive/My Drive/Colab Notebooks/Data')
!pwd

view this answer for detailed explaination https://stackoverflow.com/a/61636734/11535267

How can I include null values in a MIN or MAX?

Use IsNull

SELECT recordid, MIN(startdate), MAX(IsNull(enddate, Getdate()))
FROM tmp 
GROUP BY recordid

I've modified MIN in the second instruction to MAX

What’s the best way to check if a file exists in C++? (cross platform)

Use stat(), if it is cross-platform enough for your needs. It is not C++ standard though, but POSIX.

On MS Windows there is _stat, _stat64, _stati64, _wstat, _wstat64, _wstati64.

Drawing an SVG file on a HTML5 canvas

Mozilla has a simple way for drawing SVG on canvas called "Drawing DOM objects into a canvas"

Difference between using "chmod a+x" and "chmod 755"

Yes - different

chmod a+x will add the exec bits to the file but will not touch other bits. For example file might be still unreadable to others and group.

chmod 755 will always make the file with perms 755 no matter what initial permissions were.

This may or may not matter for your script.

How can I see an the output of my C programs using Dev-C++?

i think you should link your project in console mode

just press Ctrl+h and in General tab select console.

Oracle select most recent date record

you can't use aliases from select list inside the WHERE clause (because of the Order of Evaluation of a SELECT statement)

also you cannot use OVER clause inside WHERE clause - "You can specify analytic functions with this clause in the select list or ORDER BY clause." (citation from docs.oracle.com)

select *
from (select
  staff_id, site_id, pay_level, date, 
  max(date) over (partition by staff_id) max_date
  from owner.table
  where end_enrollment_date is null
)
where date = max_date

Cannot GET / Nodejs Error

I think you're missing your routes, you need to define at least one route for example '/' to index.

e.g.

app.get('/', function (req, res) {
  res.render('index', {});
});

Convert a list to a data frame

Every solution I have found seems to only apply when every object in a list has the same length. I needed to convert a list to a data.frame when the length of the objects in the list were of unequal length. Below is the base R solution I came up with. It no doubt is very inefficient, but it does seem to work.

x1 <- c(2, 13)
x2 <- c(2, 4, 6, 9, 11, 13)
x3 <- c(1, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 9, 9, 10, 11, 11, 12, 13, 13)
my.results <- list(x1, x2, x3)

# identify length of each list
my.lengths <- unlist(lapply(my.results, function (x) { length(unlist(x))}))
my.lengths
#[1]  2  6 20

# create a vector of values in all lists
my.values <- as.numeric(unlist(c(do.call(rbind, lapply(my.results, as.data.frame)))))
my.values
#[1]  2 13  2  4  6  9 11 13  1  1  2  3  3  4  5  5  6  7  7  8  9  9 10 11 11 12 13 13

my.matrix <- matrix(NA, nrow = max(my.lengths), ncol = length(my.lengths))

my.cumsum <- cumsum(my.lengths)

mm <- 1

for(i in 1:length(my.lengths)) {

     my.matrix[1:my.lengths[i],i] <- my.values[mm:my.cumsum[i]]

     mm <- my.cumsum[i]+1

}

my.df <- as.data.frame(my.matrix)
my.df
#   V1 V2 V3
#1   2  2  1
#2  13  4  1
#3  NA  6  2
#4  NA  9  3
#5  NA 11  3
#6  NA 13  4
#7  NA NA  5
#8  NA NA  5
#9  NA NA  6
#10 NA NA  7
#11 NA NA  7
#12 NA NA  8
#13 NA NA  9
#14 NA NA  9
#15 NA NA 10
#16 NA NA 11
#17 NA NA 11
#18 NA NA 12
#19 NA NA 13
#20 NA NA 13

Make div (height) occupy parent remaining height

Unless I am misunderstanding, you can just add height: 100%; and overflow:hidden; to #down.

#down { 
    background:pink; 
    height:100%; 
    overflow:hidden;
}?

Live DEMO

Edit: Since you do not want to use overflow:hidden;, you can use display: table; for this scenario; however, it is not supported prior to IE 8. (display: table; support)

#container { 
    width: 300px; 
    height: 300px; 
    border:1px solid red;
    display:table;
}

#up { 
    background: green;
    display:table-row;
    height:0; 
}

#down { 
    background:pink;
    display:table-row;
}?

Live DEMO

Note: You have said that you want the #down height to be #container height minus #up height. The display:table; solution does exactly that and this jsfiddle will portray that pretty clearly.

Programs & Examples On #Release mode

Setting the correct encoding when piping stdout in Python

What is the default scope of a method in Java?

React Native version mismatch

PHPDoc type hinting for array of objects?

What useful i was going to add posting this answer

Auto submit form on page load

xls to csv converter

How to detect if a stored procedure already exists

How do I delete everything in Redis?

Reading Datetime value From Excel sheet

How do I access properties of a javascript object if I don't know the names?

Node.js - How to send data from html to express

Deserializing JSON data to C# using JSON.NET

JavaScript onclick redirect

Collision resolution in Java HashMap

Error - trustAnchors parameter must be non-empty

Convert a numpy.ndarray to string(or bytes) and convert it back to numpy.ndarray

Javascript onclick hide div

Is there a command for formatting HTML in the Atom editor?

Visual Studio Code Automatic Imports

How to find the extension of a file in C#?

Is it better practice to use String.format over string Concatenation in Java?

jQuery add blank option to top of list and make selected to existing dropdown

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CollegeWebsite]]

How to loop through each and every row, column and cells in a GridView and get its value

Maven is not working in Java 8 when Javadoc tags are incomplete

JavaScript Extending Class

Summary:

ES 2015 Classes:

Factory function using Object.create():

java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory

Design Android EditText to show error message as described by google

Index of Currently Selected Row in DataGridView

Android emulator not able to access the internet

Why dividing two integers doesn't get a float?

How to access private data members outside the class without making "friend"s?

SQL Query to add a new column after an existing column in SQL Server 2005

Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

Hard reset of a single file

Is there a decorator to simply cache function return values?

How to fix curl: (60) SSL certificate: Invalid certificate chain

Recursive file search using PowerShell

Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?

The entity type <type> is not part of the model for the current context

How to print a list in Python "nicely"

How to find if element with specific id exists or not

jQuery to retrieve and set selected option value of html select element

Accessing JSON object keys having spaces

How to trap on UIViewAlertForUnsatisfiableConstraints?

Ruby String to Date Conversion

How to use range-based for() loop with std::map?

From a Sybase Database, how I can get table description ( field names and types)?

Conditional replacement of values in a data.frame

What is the difference between .NET Core and .NET Standard Class Library project types?

What's the difference between SortedList and SortedDictionary?

What is the use of static synchronized method in java?

Why am I getting "IndentationError: expected an indented block"?

How to retrieve GET parameters from JavaScript

Express.js req.body undefined

Openstreetmap: embedding map in webpage (like Google Maps)

Oracle 10g: Extract data (select) from XML (CLOB Type)

How to call a function within class?

How to install beautiful soup 4 with python 2.7 on windows

Vertically aligning text next to a radio button

IsNullOrEmpty with Object

How to manage local vs production settings in Django?

Change DataGrid cell colour based on values

Javascript isnull

JQuery Calculate Day Difference in 2 date textboxes

How to get child element by class name?

In nodeJs is there a way to loop through an array without using array size?

How to use Git?

How to find the mime type of a file in python?

How do I compile a Visual Studio project from the command-line?

Should I use typescript? or I can just use ES6?

ANTLR: Is there a simple example?

ImportError: DLL load failed: %1 is not a valid Win32 application

How to get anchor text/href on click using jQuery?

Can't concat bytes to str

Factory function using `Object.create()`: