Programs & Examples On #List.selectedvalue

Installation error: INSTALL_FAILED_OLDER_SDK

Go in your project's build.cradle file and add

defaultConfig {
    minSdkVersion versions.minSdk

}`

This makes it that your application conforms to the minimum SDK your device is running.

How to convert a byte array to Stream

I am using as what John Rasch said:

Stream streamContent = taxformUpload.FileContent;

Object of custom type as dictionary key

You override __hash__ if you want special hash-semantics, and __cmp__ or __eq__ in order to make your class usable as a key. Objects who compare equal need to have the same hash value.

Python expects __hash__ to return an integer, returning Banana() is not recommended :)

User defined classes have __hash__ by default that calls id(self), as you noted.

There is some extra tips from the documentation.:

Classes which inherit a __hash__() method from a parent class but change the meaning of __cmp__() or __eq__() such that the hash value returned is no longer appropriate (e.g. by switching to a value-based concept of equality instead of the default identity based equality) can explicitly flag themselves as being unhashable by setting __hash__ = None in the class definition. Doing so means that not only will instances of the class raise an appropriate TypeError when a program attempts to retrieve their hash value, but they will also be correctly identified as unhashable when checking isinstance(obj, collections.Hashable) (unlike classes which define their own __hash__() to explicitly raise TypeError).

How do I reverse a C++ vector?

You can use std::reverse like this

std::reverse(str.begin(), str.end());

How do I find where JDK is installed on my windows machine?

Plain and simple on Windows platforms:

where java

ERROR 1049 (42000): Unknown database

blog_development doesn't exist

You can see this in sql by the 0 rows affected message

create it in mysql with

mysql> create database blog_development

However as you are using rails you should get used to using

$ rake db:create

to do the same task. It will use your database.yml file settings, which should include something like:

development:
  adapter: mysql2
  database: blog_development
  pool: 5

Also become familiar with:

$ rake db:migrate  # Run the database migration
$ rake db:seed     # Run thew seeds file create statements
$ rake db:drop     # Drop the database

'cout' was not declared in this scope

Use std::cout, since cout is defined within the std namespace. Alternatively, add a using std::cout; directive.

What is difference between sleep() method and yield() method of multi threading?

sleep() causes the thread to definitely stop executing for a given amount of time; if no other thread or process needs to be run, the CPU will be idle (and probably enter a power saving mode).

yield() basically means that the thread is not doing anything particularly important and if any other threads or processes need to be run, they should. Otherwise, the current thread will continue to run.

Getting Exception(org.apache.poi.openxml4j.exception - no content type [M1.13]) when reading xlsx file using Apache POI?

You might also see this error if you attempt to parse the same file twice from the same source.

I was parsing the file once to validate and again (from the same InputStream) to process - this produced the above error.

To get round this I parsed the source file into 2 different InputStreams, one to validate and one to process.

Truncate Decimal number not Round Off

Try this:

decimal original = GetSomeDecimal(); // 22222.22939393
int number1 = (int)original; // contains only integer value of origina number
decimal temporary = original - number1; // contains only decimal value of original number
int decimalPlaces = GetDecimalPlaces(); // 3
temporary *= (Math.Pow(10, decimalPlaces)); // moves some decimal places to integer
temporary = (int)temporary; // removes all decimal places
temporary /= (Math.Pow(10, decimalPlaces)); // moves integer back to decimal places
decimal result = original + temporary; // add integer and decimal places together

It can be writen shorter, but this is more descriptive.

EDIT: Short way:

decimal original = GetSomeDecimal(); // 22222.22939393
int decimalPlaces = GetDecimalPlaces(); // 3
decimal result = ((int)original) + (((int)(original * Math.Pow(10, decimalPlaces)) / (Math.Pow(10, decimalPlaces));

How do I initialize an empty array in C#?

string[] a = new string[0];

or short notation:

string[] a = { };

The preferred way now is:

var a = Array.Empty<string>();

I have written a short regular expression that you can use in Visual Studio if you want to replace zero-length allocations e.g. new string[0]. Use Find (search) in Visual Studio with Regular Expression option turned on:

new[ ][a-zA-Z0-9]+\[0\]

Now Find All or F3 (Find Next) and replace all with Array.Empty<…>() !

Setting environment variables for accessing in PHP when using Apache

Something along the lines:

<VirtualHost hostname:80>
   ...
   SetEnv VARIABLE_NAME variable_value
   ...
</VirtualHost>

java IO Exception: Stream Closed

Don't call write.close() in writeToFile().

How to deal with "java.lang.OutOfMemoryError: Java heap space" error?

I have faced same problem from java heap size.

I have two solutions if you are using java 5(1.5).

  1. just install jdk1.6 and go to the preferences of eclipse and set the jre path of jav1 1.6 as you have installed.

  2. Check your VM argument and let it be whatever it is. just add one line below of all the arguments present in VM arguments as -Xms512m -Xmx512m -XX:MaxPermSize=...m(192m).

I think it will work...

How do I force git to checkout the master branch and remove carriage returns after I've normalized files using the "text" attribute?

Ahah! Checkout the previous commit, then checkout the master.

git checkout HEAD^
git checkout -f master

TypeError: sequence item 0: expected string, int found

Replace

values = ",".join(value_list)

with

values = ','.join([str(i) for i in value_list])

OR

values = ','.join(str(value_list)[1:-1])

ListView with OnItemClickListener

if list item view contains button or checkbox or imagebutton, the onitemclicklistener and onitemlongclicklistener not working due to it has own onclick listener.

set focusable as false

holder.button.setFocusable(false);

Aggregate multiple columns at once

We can use the formula method of aggregate. The variables on the 'rhs' of ~ are the grouping variables while the . represents all other variables in the 'df1' (from the example, we assume that we need the mean for all the columns except the grouping), specify the dataset and the function (mean).

aggregate(.~id1+id2, df1, mean)

Or we can use summarise_each from dplyr after grouping (group_by)

library(dplyr)
df1 %>%
    group_by(id1, id2) %>% 
    summarise_each(funs(mean))

Or using summarise with across (dplyr devel version - ‘0.8.99.9000’)

df1 %>% 
    group_by(id1, id2) %>%
    summarise(across(starts_with('val'), mean))

Or another option is data.table. We convert the 'data.frame' to 'data.table' (setDT(df1), grouped by 'id1' and 'id2', we loop through the subset of data.table (.SD) and get the mean.

library(data.table)
setDT(df1)[, lapply(.SD, mean), by = .(id1, id2)] 

data

df1 <- structure(list(id1 = c("a", "a", "a", "a", "b", "b", 
"b", "b"
), id2 = c("x", "x", "y", "y", "x", "y", "x", "y"), 
val1 = c(1L, 
2L, 3L, 4L, 1L, 4L, 3L, 2L), val2 = c(9L, 4L, 5L, 9L, 7L, 4L, 
9L, 8L)), .Names = c("id1", "id2", "val1", "val2"), 
class = "data.frame", row.names = c("1", 
"2", "3", "4", "5", "6", "7", "8"))

How to write to the Output window in Visual Studio?

Useful tip - if you use __FILE__ and __LINE__ then format your debug as:

"file(line): Your output here"

then when you click on that line in the output window Visual Studio will jump directly to that line of code. An example:

#include <Windows.h>
#include <iostream>
#include <sstream>

void DBOut(const char *file, const int line, const WCHAR *s)
{
    std::wostringstream os_;
    os_ << file << "(" << line << "): ";
    os_ << s;
    OutputDebugStringW(os_.str().c_str());
}

#define DBOUT(s)       DBOut(__FILE__, __LINE__, s)

I wrote a blog post about this so I always knew where I could look it up: https://windowscecleaner.blogspot.co.nz/2013/04/debug-output-tricks-for-visual-studio.html

How to increase buffer size in Oracle SQL Developer to view all records?

https://forums.oracle.com/forums/thread.jspa?threadID=447344

The pertinent section reads:

There's no setting to fetch all records. You wouldn't like SQL Developer to fetch for minutes on big tables anyway. If, for 1 specific table, you want to fetch all records, you can do Control-End in the results pane to go to the last record. You could time the fetching time yourself, but that will vary on the network speed and congestion, the program (SQL*Plus will be quicker than SQL Dev because it's more simple), etc.

There is also a button on the toolbar which is a "Fetch All" button.

FWIW Be careful retrieving all records, for a very large recordset it could cause you to have all sorts of memory issues etc.

As far as I know, SQL Developer uses JDBC behind the scenes to fetch the records and the limit is set by the JDBC setMaxRows() procedure, if you could alter this (it would prob be unsupported) then you might be able to change the SQL Developer behaviour.

MySQL with Node.js

node-mysql is probably one of the best modules out there used for working with MySQL database which is actively maintained and well documented.

Why does Eclipse Java Package Explorer show question mark on some classes?

In a enabled project the small question mark (?) indicates that your file is not yet added to the SVN repository.

The small orange rectangle is an indication that your file is committed in the repository.

An asterisk (*) indicates a local change.

How can I link to a specific glibc version?

In my opinion, the laziest solution (especially if you don't rely on latest bleeding edge C/C++ features, or latest compiler features) wasn't mentioned yet, so here it is:

Just build on the system with the oldest GLIBC you still want to support.

This is actually pretty easy to do nowadays with technologies like chroot, or KVM/Virtualbox, or docker, even if you don't really want to use such an old distro directly on any pc. In detail, to make a maximum portable binary of your software I recommend following these steps:

  1. Just pick your poison of sandbox/virtualization/... whatever, and use it to get yourself a virtual older Ubuntu LTS and compile with the gcc/g++ it has in there by default. That automatically limits your GLIBC to the one available in that environment.

  2. Avoid depending on external libs outside of foundational ones: like, you should dynamically link ground-level system stuff like glibc, libGL, libxcb/X11/wayland things, libasound/libpulseaudio, possibly GTK+ if you use that, but otherwise preferrably statically link external libs/ship them along if you can. Especially mostly self-contained libs like image loaders, multimedia decoders, etc can cause less breakage on other distros (breakage can be caused e.g. if only present somewhere in a different major version) if you statically ship them.

With that approach you get an old-GLIBC-compatible binary without any manual symbol tweaks, without doing a fully static binary (that may break for more complex programs because glibc hates that, and which may cause licensing issues for you), and without setting up any custom toolchain, any custom glibc copy, or whatever.

C/C++ check if one bit is set in, i.e. int variable

The precedent answers show you how to handle bit checks, but more often then not, it is all about flags encoded in an integer, which is not well defined in any of the precedent cases.

In a typical scenario, flags are defined as integers themselves, with a bit to 1 for the specific bit it refers to. In the example hereafter, you can check if the integer has ANY flag from a list of flags (multiple error flags concatenated) or if EVERY flag is in the integer (multiple success flags concatenated).

Following an example of how to handle flags in an integer.

Live example available here: https://rextester.com/XIKE82408

//g++  7.4.0

#include <iostream>
#include <stdint.h>

inline bool any_flag_present(unsigned int value, unsigned int flags) {
    return bool(value & flags);
}

inline bool all_flags_present(unsigned int value, unsigned int flags) {
    return (value & flags) == flags;
}

enum: unsigned int {
    ERROR_1 = 1U,
    ERROR_2 = 2U, // or 0b10
    ERROR_3 = 4U, // or 0b100
    SUCCESS_1 = 8U,
    SUCCESS_2 = 16U,
    OTHER_FLAG = 32U,
};

int main(void)
{
    unsigned int value = 0b101011; // ERROR_1, ERROR_2, SUCCESS_1, OTHER_FLAG
    unsigned int all_error_flags = ERROR_1 | ERROR_2 | ERROR_3;
    unsigned int all_success_flags = SUCCESS_1 | SUCCESS_2;
    
    std::cout << "Was there at least one error: " << any_flag_present(value, all_error_flags) << std::endl;
    std::cout << "Are all success flags enabled: " << all_flags_present(value, all_success_flags) << std::endl;
    std::cout << "Is the other flag enabled with eror 1: " << all_flags_present(value, ERROR_1 | OTHER_FLAG) << std::endl;
    return 0;
}

How do I get the raw request body from the Request.Content object using .net 4 api endpoint

In your comment on @Kenneth's answer you're saying that ReadAsStringAsync() is returning empty string.

That's because you (or something - like model binder) already read the content, so position of internal stream in Request.Content is on the end.

What you can do is this:

public static string GetRequestBody()
{
    var bodyStream = new StreamReader(HttpContext.Current.Request.InputStream);
    bodyStream.BaseStream.Seek(0, SeekOrigin.Begin);
    var bodyText = bodyStream.ReadToEnd();
    return bodyText;
}

Cannot open new Jupyter Notebook [Permission Denied]

I encountered same problem when I installed latest version of anaconda navigator 64 bit on windows 10.

I got to know that INSTALLING 32 BIT VERSION ON WINDOWS 10 will solve the issue. It worked for me. Jupyter is running smoothly now.

Remove useless zero digits from decimals in PHP

The following is much simpler

if(floor($num) == $num) {
    echo number_format($num);
} else {
    echo $num;
}

How can I convert a string to boolean in JavaScript?

Remember to match case:

var isTrueSet = (myValue.toLowerCase() === 'true');

Also, if it's a form element checkbox, you can also detect if the checkbox is checked:

var isTrueSet = document.myForm.IS_TRUE.checked;

Assuming that if it is checked, it is "set" equal to true. This evaluates as true/false.

Should URL be case sensitive?

URL characters are converted into hex code (if you've ever noticed spaces in URLs being displayed as %20, etc.), and since lower and upper case have different hex values, it makes perfect sense that URLs are most definitely case sensitive. However the spirit of the question seems to be SHOULD that be the standard and I say no, but they are. Its up to the developer/provider to account for this in their code if they want it to work regardless for an end user.

How to use NSURLConnection to connect with SSL for an untrusted cert?

Ideally, there should only be two scenarios of when an iOS application would need to accept an un-trusted certificate.

Scenario A: You are connected to a test environment which is using a self-signed certificate.

Scenario B: You are Proxying HTTPS traffic using a MITM Proxy like Burp Suite, Fiddler, OWASP ZAP, etc. The Proxies will return a certificate signed by a self-signed CA so that the proxy is able to capture HTTPS traffic.

Production hosts should never use un-trusted certificates for obvious reasons.

If you need to have the iOS simulator accept an un-trusted certificate for testing purposes it is highly recommended that you do not change application logic in order disable the built in certificate validation provided by the NSURLConnection APIs. If the application is released to the public without removing this logic, it will be susceptible to man-in-the-middle attacks.

The recommended way to accept un-trusted certificates for testing purposes is to import the Certificate Authority(CA) certificate which signed the certificate onto your iOS Simulator or iOS device. I wrote up a quick blog post which demonstrates how to do this which an iOS Simulator at:

accepting untrusted certificates using the ios simulator

Streaming Audio from A URL in Android using MediaPlayer?

Use

 mediaplayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
 mediaplayer.prepareAsync();
 mediaplayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
      @Override
      public void onPrepared(MediaPlayer mp) {
          mediaplayer.start();
      }
 });

change html input type by JS?

Changing the type of an <input type=password> throws a security error in some browsers (old IE and Firefox versions).

You’ll need to create a new input element, set its type to the one you want, and clone all other properties from the existing one.

I do this in my jQuery placeholder plugin: https://github.com/mathiasbynens/jquery-placeholder/blob/master/jquery.placeholder.js#L80-84

To work in Internet Explorer:

  • dynamically create a new element
  • copy the properties of the old element into the new element
  • set the type of the new element to the new type
  • replace the old element with the new element

The function below accomplishes the above tasks for you:

<script>
function changeInputType(oldObject, oType) {
    var newObject = document.createElement('input');
    newObject.type = oType;
    if(oldObject.size) newObject.size = oldObject.size;
    if(oldObject.value) newObject.value = oldObject.value;
    if(oldObject.name) newObject.name = oldObject.name;
    if(oldObject.id) newObject.id = oldObject.id;
    if(oldObject.className) newObject.className = oldObject.className;
    oldObject.parentNode.replaceChild(newObject,oldObject);
    return newObject;
}
</script>

How to set Spring profile from system variable?

You can set the spring profile by supplying -Dspring.profiles.active=<env>

For java files in source(src) directory, you can use by System.getProperty("spring.profiles.active")

For java files in test directory you can supply

  • SPRING_PROFILES_ACTIVE to <env>

OR

Since, "environment", "jvmArgs" and "systemProperties" are ignored for the "test" task. In root build.gradle add a task to set jvm property and environment variable.

test {
    def profile = System.properties["spring.profiles.active"]
    systemProperty "spring.profiles.active",profile
    environment "SPRING.PROFILES_ACTIVE", profile
    println "Running ${project} tests with profile: ${profile}"
}

Remove Item in Dictionary based on Value

You can use the following as extension method

 public static void RemoveByValue<T,T1>(this Dictionary<T,T1> src , T1 Value)
    {
        foreach (var item in src.Where(kvp => kvp.Value.Equals( Value)).ToList())
        {
            src.Remove(item.Key);
        }
    }

How can I detect if a selector returns null?

This is in the JQuery documentation:

http://learn.jquery.com/using-jquery-core/faq/how-do-i-test-whether-an-element-exists/

  alert( $( "#notAnElement" ).length ? 'Not null' : 'Null' );

How do you pass a function as a parameter in C?

Pass address of a function as parameter to another function as shown below

#include <stdio.h>

void print();
void execute(void());

int main()
{
    execute(print); // sends address of print
    return 0;
}

void print()
{
    printf("Hello!");
}

void execute(void f()) // receive address of print
{
    f();
}

Also we can pass function as parameter using function pointer

#include <stdio.h>

void print();
void execute(void (*f)());

int main()
{
    execute(&print); // sends address of print
    return 0;
}

void print()
{
    printf("Hello!");
}

void execute(void (*f)()) // receive address of print
{
    f();
}

Add data dynamically to an Array

There are quite a few ways to work with dynamic arrays in PHP. Initialise an array:

$array = array();

Add to an array:

$array[] = "item"; // for your $arr1 
$array[$key] = "item"; // for your $arr2
array_push($array, "item", "another item");

Remove from an array:

$item = array_pop($array);
$item = array_shift($array);
unset($array[$key]);

There are plenty more ways, these are just some examples.

How to import a jar in Eclipse

  1. Right Click on the Project.
  2. Click on Build Path.
  3. Click On Configure Build Path.
  4. Under Libraries, Click on Add Jar or Add External Jar.

How to use ESLint with Jest

To complete Zachary's answer, here is a workaround for the "extend in overrides" limitation of eslint config :

overrides: [
  Object.assign(
    {
      files: [ '**/*.test.js' ],
      env: { jest: true },
      plugins: [ 'jest' ],
    },
    require('eslint-plugin-jest').configs.recommended
  )
]

From https://github.com/eslint/eslint/issues/8813#issuecomment-320448724

Object of class stdClass could not be converted to string - laravel

Try this simple in one line of code:-

$data= json_decode( json_encode($data), true);

Hope it helps :)

Does WhatsApp offer an open API?

WhatsApp does not have a API available for public use. As you put it, it's a closed system.

However, they provide several other ways in which your iPhone application can interact with WhatsApp: through custom URL schemes, share extension and through the Document Interaction API.

See this WhatsApp FAQ article.

Query comparing dates in SQL

please try with below query

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
convert(datetime, convert(varchar(10), created_date, 102))  <= convert(datetime,'2013-04-12')

How Long Does it Take to Learn Java for a Complete Newbie?

The main problem you're having is that you're learning programming for the first time with Java and I think Java isn't the best language to start.

I suppose that you're addressing a work project, Is this the case? That pressure might make things worse. Depending on how complex the project is you might success but learning Java in 10 weeks without background knowledge is another issue.

Clearing an input text field in Angular2

There are two additional ways to do it apart from the two methods mentioned in @PradeepJain's answer.

I would suggest not to use this approach and to fall back to this only as a last resort if you are not using [(ngModel)] directive and also not using data binding via [value]. Read this for more info.

Using ElementRef

app.component.html

<div>
      <input type="text" #searchInput placeholder="Search...">
      <button (click)="clearSearchInput()">Clear</button>
</div>

app.component.ts

export class App {
  @ViewChild('searchInput') searchInput: ElementRef;

  clearSearchInput(){
     this.searchInput.nativeElement.value = '';
  }
}

Using FormGroup

app.component.html

<form [formGroup]="form">
    <div *ngIf="first.invalid"> Name is too short. </div>
    <input formControlName="first" placeholder="First name">
    <input formControlName="last" placeholder="Last name">
    <button type="submit">Submit</button>
</form>
<button (click)="setValue()">Set preset value</button>
<button (click)="clearInputMethod1()">Clear Input Method 1</button>
<button (click)="clearInputMethod2()">Clear Input Method 2</button>

app.component.ts

export class AppComponent {
  form = new FormGroup({
    first: new FormControl('Nancy', Validators.minLength(2)),
    last: new FormControl('Drew'),
  });
  get first(): any { return this.form.get('first'); }
  get last(): any { return this.form.get('last'); }
  clearInputMethod1() { this.first.reset(); this.last.reset(); }
  clearInputMethod2() { this.form.setValue({first: '', last: ''}); }
  setValue() { this.form.setValue({first: 'Nancy', last: 'Drew'}); }
}

Try it out on stackblitz Clearing input in a FormGroup

What is the meaning of the term "thread-safe"?

In essence, many things can go wrong in a multi threaded environment (instructions reordering, partially constructed objects, same variable having different values in different threads because of caching at the CPU level etc.).

I like the definition given by Java Concurrency in Practice:

A [portion of code] is thread-safe if it behaves correctly when accessed from multiple threads, regardless of the scheduling or interleaving of the execution of those threads by the runtime environment, and with no additional synchronization or other coordination on the part of the calling code.

By correctly they mean that the program behaves in compliance with its specifications.

Contrived example

Imagine that you implement a counter. You could say that it behaves correctly if:

  • counter.next() never returns a value that has already been returned before (we assume no overflow etc. for simplicity)
  • all values from 0 to the current value have been returned at some stage (no value is skipped)

A thread safe counter would behave according to those rules regardless of how many threads access it concurrently (which would typically not be the case of a naive implementation).

Note: cross-post on Programmers

Escape sequence \f - form feed - what exactly is it?

If you were programming for a 1980s-style printer, it would eject the paper and start a new page. You are virtually certain to never need it.

http://en.wikipedia.org/wiki/Form_feed

Generate pdf from HTML in div using Javascript

As mentioned, you should use jsPDF and html2canvas. I've also found a function inside issues of jsPDF which splits automatically your pdf into multiple pages (sources)

function makePDF() {

    var quotes = document.getElementById('container-fluid');

    html2canvas(quotes, {
        onrendered: function(canvas) {

        //! MAKE YOUR PDF
        var pdf = new jsPDF('p', 'pt', 'letter');

        for (var i = 0; i <= quotes.clientHeight/980; i++) {
            //! This is all just html2canvas stuff
            var srcImg  = canvas;
            var sX      = 0;
            var sY      = 980*i; // start 980 pixels down for every new page
            var sWidth  = 900;
            var sHeight = 980;
            var dX      = 0;
            var dY      = 0;
            var dWidth  = 900;
            var dHeight = 980;

            window.onePageCanvas = document.createElement("canvas");
            onePageCanvas.setAttribute('width', 900);
            onePageCanvas.setAttribute('height', 980);
            var ctx = onePageCanvas.getContext('2d');
            // details on this usage of this function: 
            // https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Using_images#Slicing
            ctx.drawImage(srcImg,sX,sY,sWidth,sHeight,dX,dY,dWidth,dHeight);

            // document.body.appendChild(canvas);
            var canvasDataURL = onePageCanvas.toDataURL("image/png", 1.0);

            var width         = onePageCanvas.width;
            var height        = onePageCanvas.clientHeight;

            //! If we're on anything other than the first page,
            // add another page
            if (i > 0) {
                pdf.addPage(612, 791); //8.5" x 11" in pts (in*72)
            }
            //! now we declare that we're working on that page
            pdf.setPage(i+1);
            //! now we add content to that page!
            pdf.addImage(canvasDataURL, 'PNG', 20, 40, (width*.62), (height*.62));

        }
        //! after the for loop is finished running, we save the pdf.
        pdf.save('test.pdf');
    }
  });
}

How do I join two lists in Java?

public static <T> List<T> merge(@Nonnull final List<T>... list) {
    // calculate length first
    int mergedLength = 0;
    for (List<T> ts : list) {
      mergedLength += ts.size();
    }

    final List<T> mergedList = new ArrayList<>(mergedLength);

    for (List<T> ts : list) {
      mergedList.addAll(ts);
    }

    return mergedList;
  }

Expression must have class type

a is a pointer. You need to use->, not .

How can I make a SQL temp table with primary key and auto-incrementing field?

If you're just doing some quick and dirty temporary work, you can also skip typing out an explicit CREATE TABLE statement and just make the temp table with a SELECT...INTO and include an Identity field in the select list.

select IDENTITY(int, 1, 1) as ROW_ID,
       Name
into #tmp
from (select 'Bob' as Name union all
      select 'Susan' as Name union all
      select 'Alice' as Name) some_data

select *
from #tmp

UIButton title text color

I created a custom class MyButton extended from UIButton. Then added this inside the Identity Inspector:

enter image description here

After this, change the button type to Custom:

enter image description here

Then you can set attributes like textColor and UIFont for your UIButton for the different states:

enter image description here

Then I also created two methods inside MyButton class which I have to call inside my code when I want a UIButton to be displayed as highlighted:

- (void)changeColorAsUnselection{
    [self setTitleColor:[UIColor colorFromHexString:acColorGreyDark] 
               forState:UIControlStateNormal & 
                        UIControlStateSelected & 
                        UIControlStateHighlighted];
}

- (void)changeColorAsSelection{
    [self setTitleColor:[UIColor colorFromHexString:acColorYellow] 
               forState:UIControlStateNormal & 
                        UIControlStateHighlighted & 
                        UIControlStateSelected];
}

You have to set the titleColor for normal, highlight and selected UIControlState because there can be more than one state at a time according to the documentation of UIControlState. If you don't create these methods, the UIButton will display selection or highlighting but they won't stay in the UIColor you setup inside the UIInterface Builder because they are just available for a short display of a selection, not for displaying selection itself.

Is it possible to decrypt MD5 hashes?

MD5 is a hashing algorithm, you can not revert the hash value.

You should add "change password feature", where the user gives another password, calculates the hash and store it as a new password.

How to auto-reload files in Node.js?

node-supervisor is awesome

usage to restart on save:

npm install supervisor -g
supervisor app.js

by isaacs - http://github.com/isaacs/node-supervisor

Set UITableView content inset permanently

Probably it was some sort of my mistake because of me messing with autolayouts and storyboard but I found an answer.

You have to take care of this little guy in View Controller's Attribute Inspector asvi

It must be unchecked so the default contentInset wouldn't be set after any change. After that it is just adding one-liner to viewDidLoad:

[self.tableView setContentInset:UIEdgeInsetsMake(108, 0, 0, 0)]; // 108 is only example

iOS 11, Xcode 9 update

Looks like the previous solution is no longer a correct one if it comes to iOS 11 and Xcode 9. automaticallyAdjustsScrollViewInsets has been deprecated and right now to achieve similar effect you have to go to Size Inspector where you can find this: enter image description here
Also, you can achieve the same in code:

if #available(iOS 11.0, *) {
    scrollView.contentInsetAdjustmentBehavior = .never
} else {
    automaticallyAdjustsScrollViewInsets = false
}

How to test multiple variables against a value?

Problem

While the pattern for testing multiple values

>>> 2 in {1, 2, 3}
True
>>> 5 in {1, 2, 3}
False

is very readable and is working in many situation, there is one pitfall:

>>> 0 in {True, False}
True

But we want to have

>>> (0 is True) or (0 is False)
False

Solution

One generalization of the previous expression is based on the answer from ytpillai:

>>> any([0 is True, 0 is False])
False

which can be written as

>>> any(0 is item for item in (True, False))
False

While this expression returns the right result it is not as readable as the first expression :-(

gcc error: wrong ELF class: ELFCLASS64

I think that coreset.o was compiled for 64-bit, and you are linking it with a 32-bit computation.o.

You can try to recompile computation.c with the '-m64' flag of gcc(1)

How to deal with http status codes other than 200 in Angular 2

Yes you can handle with the catch operator like this and show alert as you want but firstly you have to import Rxjs for the same like this way

import {Observable} from 'rxjs/Rx';

return this.http.request(new Request(this.requestoptions))
            .map((res: Response) => {
                if (res) {
                    if (res.status === 201) {
                        return [{ status: res.status, json: res }]
                    }
                    else if (res.status === 200) {
                        return [{ status: res.status, json: res }]
                    }
                }
            }).catch((error: any) => {
                if (error.status === 500) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 400) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 409) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 406) {
                    return Observable.throw(new Error(error.status));
                }
            });
    }

also you can handel error (with err block) that is throw by catch block while .map function,

like this -

...
.subscribe(res=>{....}
           err => {//handel here});

Update

as required for any status without checking particluar one you can try this: -

return this.http.request(new Request(this.requestoptions))
            .map((res: Response) => {
                if (res) {
                    if (res.status === 201) {
                        return [{ status: res.status, json: res }]
                    }
                    else if (res.status === 200) {
                        return [{ status: res.status, json: res }]
                    }
                }
            }).catch((error: any) => {
                if (error.status < 400 ||  error.status ===500) {
                    return Observable.throw(new Error(error.status));
                }
            })
            .subscribe(res => {...},
                       err => {console.log(err)} );

Play/pause HTML 5 video using JQuery

Just as a note, make sure you check if the browser supports the video function, before you try to invoke it:

if($('#movie1')[0].play)
    $('#movie1')[0].play();

That will prevent JavaScript errors on browsers that don't support the video tag.

What is "runtime"?

I'm not crazy about the other answers here; they're too vague and abstract for me. I think more in stories. Here's my attempt at a better answer.

a BASIC example

Let's say it's 1985 and you write a short BASIC program on an Apple II:

] 10 PRINT "HELLO WORLD!"
] 20 GOTO 10

So far, your program is just source code. It's not running, and we would say there is no "runtime" involved with it.

But now I run it:

] RUN

How is it actually running? How does it know how to send the string parameter from PRINT to the physical screen? I certainly didn't provide any system information in my code, and PRINT itself doesn't know anything about my system.

Instead, RUN is actually a program itself -- its code tells it how to parse my code, how to execute it, and how to send any relevant requests to the computer's operating system. The RUN program provides the "runtime" environment that acts as a layer between the operating system and my source code. The operating system itself acts as part of this "runtime", but we usually don't mean to include it when we talk about a "runtime" like the RUN program.

Types of compilation and runtime

Compiled binary languages

In some languages, your source code must be compiled before it can be run. Some languages compile your code into machine language -- it can be run by your operating system directly. This compiled code is often called "binary" (even though every other kind of file is also in binary :).

In this case, there is still a minimal "runtime" involved -- but that runtime is provided by the operating system itself. The compile step means that many statements that would cause your program to crash are detected before the code is ever run.

C is one such language; when you run a C program, it's totally able to send illegal requests to the operating system (like, "give me control of all of the memory on the computer, and erase it all"). If an illegal request is hit, usually the OS will just kill your program and not tell you why, and dump the contents of that program's memory at the time it was killed to a .dump file that's pretty hard to make sense of. But sometimes your code has a command that is a very bad idea, but the OS doesn't consider it illegal, like "erase a random bit of memory this program is using"; that can cause super weird problems that are hard to get to the bottom of.

Bytecode languages

Other languages compile your code into a language that the operating system can't read directly, but a specific runtime program can read your compiled code. This compiled code is often called "bytecode".

The more elaborate this runtime program is, the more extra stuff it can do on the side that your code did not include (even in the libraries you use) -- for instance, the Java runtime environment ("JRE") can keep track of memory assignments that are no longer needed, and tell the operating system it's safe to reuse that memory for something else, and it can catch situations where your code would try to send an illegal request to the operating system, and instead exit with a readable error.

All of this overhead makes them slower than compiled binary languages, but it makes the runtime powerful and flexible; in some cases, it can even pull in other code after it starts running, without having to start over. The compile step means that many statements that would cause your program to crash are detected before the code is ever run; and the powerful runtime can keep your code from doing stupid things (e.g., you can't "erase a random bit of memory this program is using").

Scripting languages

Still other languages don't precompile your code at all; the runtime does all of the work of reading your code line by line, interpreting it and executing it. This makes them even slower than "bytecode" languages, but also even more flexible; in some cases, you can even fiddle with your source code as it runs! Though it also means that you can have a totally illegal statement in your code, and it could sit there in your production code without drawing attention, until one day it is run and causes a crash.

These are generally called "scripting" languages; they include Javascript, Python, Perl, and PHP. Some of these provide cases where you can choose to compile the code to improve its speed (e.g., Javascript's WebAssembly project, and Python's trans-compilation to C code). So Javascript can allow users on a website to see the exact code that is running, since their browser is providing the runtime.

This flexibility also allows for innovations in runtime environments, like node.js, which is both a code library and a runtime environment that can run your Javascript code as a server, which involves behaving very differently than if you tried to run the same code on a browser.

What is the method for converting radians to degrees?

a complete circle in radians is 2*pi. A complete circle in degrees is 360. To go from degrees to radians, it's (d/360) * 2*pi, or d*pi/180.

Uri content://media/external/file doesn't exist for some devices

Most probably it has to do with caching on the device. Catching the exception and ignoring is not nice but my problem was fixed and it seems to work.

Java JDBC - How to connect to Oracle using Service Name instead of SID

Try this: jdbc:oracle:thin:@oracle.hostserver2.mydomain.ca:1522/ABCD

Edit: per comment below this is actualy correct: jdbc:oracle:thin:@//oracle.hostserver2.mydomain.ca:1522/ABCD (note the //)

Here is a link to a helpful article

PHP & localStorage;

localStorage is something that is kept on the client side. There is no data transmitted to the server side.

You can only get the data with JavaScript and you can send it to the server side with Ajax.

Docker error : no space left on device

In my case I didn't have so many images/containers, but the build cache was filling up my Docker Disk.

You can see that this is the problem by running

docker system df

Output:

TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              22                  13                  7.581GB             3.899GB (51%)
Containers          15                  0                   2.166GB             2.166GB (100%)
Local Volumes       4                   4                   550.2MB             0B (0%)
Build Cache         611                 0                   43.83GB             43.83GB!!!!!!!!!

The command below solves that issue

docker builder prune

How to check if a std::thread is still running?

An easy solution is to have a boolean variable that the thread sets to true on regular intervals, and that is checked and set to false by the thread wanting to know the status. If the variable is false for to long then the thread is no longer considered active.

A more thread-safe way is to have a counter that is increased by the child thread, and the main thread compares the counter to a stored value and if the same after too long time then the child thread is considered not active.

Note however, there is no way in C++11 to actually kill or remove a thread that has hanged.

Edit How to check if a thread has cleanly exited or not: Basically the same technique as described in the first paragraph; Have a boolean variable initialized to false. The last thing the child thread does is set it to true. The main thread can then check that variable, and if true do a join on the child thread without much (if any) blocking.

Edit2 If the thread exits due to an exception, then have two thread "main" functions: The first one have a try-catch inside which it calls the second "real" main thread function. This first main function sets the "have_exited" variable. Something like this:

bool thread_done = false;

void *thread_function(void *arg)
{
    void *res = nullptr;

    try
    {
        res = real_thread_function(arg);
    }
    catch (...)
    {
    }

    thread_done = true;

    return res;
}

Build .NET Core console application to output an EXE

The following will produce, in the output directory,

  • all the package references
  • the output assembly
  • the bootstrapping exe

But it does not contain all .NET Core runtime assemblies.

<PropertyGroup>
  <Temp>$(SolutionDir)\packaging\</Temp>
</PropertyGroup>

<ItemGroup>
  <BootStrapFiles Include="$(Temp)hostpolicy.dll;$(Temp)$(ProjectName).exe;$(Temp)hostfxr.dll;"/>
</ItemGroup>

<Target Name="GenerateNetcoreExe"
        AfterTargets="Build"
        Condition="'$(IsNestedBuild)' != 'true'">
  <RemoveDir Directories="$(Temp)" />
  <Exec
    ConsoleToMSBuild="true"
    Command="dotnet build $(ProjectPath) -r win-x64 /p:CopyLocalLockFileAssemblies=false;IsNestedBuild=true --output $(Temp)" >
    <Output TaskParameter="ConsoleOutput" PropertyName="OutputOfExec" />
  </Exec>
  <Copy
    SourceFiles="@(BootStrapFiles)"
    DestinationFolder="$(OutputPath)"
  />

</Target>

I wrapped it up in a sample here: https://github.com/SimonCropp/NetCoreConsole

Get yesterday's date using Date

Try this one:

private String toDate() {
    DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

    // Create a calendar object with today date. Calendar is in java.util pakage.
    Calendar calendar = Calendar.getInstance();

    // Move calendar to yesterday
    calendar.add(Calendar.DATE, -1);

    // Get current date of calendar which point to the yesterday now
    Date yesterday = calendar.getTime();

    return dateFormat.format(yesterday).toString();
}

Python 3 TypeError: must be str, not bytes with sys.stdout.write()

Python 3 handles strings a bit different. Originally there was just one type for strings: str. When unicode gained traction in the '90s the new unicode type was added to handle Unicode without breaking pre-existing code1. This is effectively the same as str but with multibyte support.

In Python 3 there are two different types:

  • The bytes type. This is just a sequence of bytes, Python doesn't know anything about how to interpret this as characters.
  • The str type. This is also a sequence of bytes, but Python knows how to interpret those bytes as characters.
  • The separate unicode type was dropped. str now supports unicode.

In Python 2 implicitly assuming an encoding could cause a lot of problems; you could end up using the wrong encoding, or the data may not have an encoding at all (e.g. it’s a PNG image).
Explicitly telling Python which encoding to use (or explicitly telling it to guess) is often a lot better and much more in line with the "Python philosophy" of "explicit is better than implicit".

This change is incompatible with Python 2 as many return values have changed, leading to subtle problems like this one; it's probably the main reason why Python 3 adoption has been so slow. Since Python doesn't have static typing2 it's impossible to change this automatically with a script (such as the bundled 2to3).

  • You can convert str to bytes with bytes('h€llo', 'utf-8'); this should produce b'H\xe2\x82\xacllo'. Note how one character was converted to three bytes.
  • You can convert bytes to str with b'H\xe2\x82\xacllo'.decode('utf-8').

Of course, UTF-8 may not be the correct character set in your case, so be sure to use the correct one.

In your specific piece of code, nextline is of type bytes, not str, reading stdout and stdin from subprocess changed in Python 3 from str to bytes. This is because Python can't be sure which encoding this uses. It probably uses the same as sys.stdin.encoding (the encoding of your system), but it can't be sure.

You need to replace:

sys.stdout.write(nextline)

with:

sys.stdout.write(nextline.decode('utf-8'))

or maybe:

sys.stdout.write(nextline.decode(sys.stdout.encoding))

You will also need to modify if nextline == '' to if nextline == b'' since:

>>> '' == b''
False

Also see the Python 3 ChangeLog, PEP 358, and PEP 3112.


1 There are some neat tricks you can do with ASCII that you can't do with multibyte character sets; the most famous example is the "xor with space to switch case" (e.g. chr(ord('a') ^ ord(' ')) == 'A') and "set 6th bit to make a control character" (e.g. ord('\t') + ord('@') == ord('I')). ASCII was designed in a time when manipulating individual bits was an operation with a non-negligible performance impact.

2 Yes, you can use function annotations, but it's a comparatively new feature and little used.

Converting String to Cstring in C++

.c_str() returns a const char*. If you need a mutable version, you will need to produce a copy yourself.

(change) vs (ngModelChange) in angular

As I have found and wrote in another topic - this applies to angular < 7 (not sure how it is in 7+)

Just for the future

we need to observe that [(ngModel)]="hero.name" is just a short-cut that can be de-sugared to: [ngModel]="hero.name" (ngModelChange)="hero.name = $event".

So if we de-sugar code we would end up with:

<select (ngModelChange)="onModelChange()" [ngModel]="hero.name" (ngModelChange)="hero.name = $event">

or

<[ngModel]="hero.name" (ngModelChange)="hero.name = $event" select (ngModelChange)="onModelChange()">

If you inspect the above code you will notice that we end up with 2 ngModelChange events and those need to be executed in some order.

Summing up: If you place ngModelChange before ngModel, you get the $event as the new value, but your model object still holds previous value. If you place it after ngModel, the model will already have the new value.

SOURCE

Left Join without duplicate rows from left table

Try an OUTER APPLY

SELECT 
    C.Content_ID,
    C.Content_Title,
    C.Content_DatePublished,
    M.Media_Id
FROM 
    tbl_Contents C
    OUTER APPLY
    (
        SELECT TOP 1 *
        FROM tbl_Media M 
        WHERE M.Content_Id = C.Content_Id 
    ) m
ORDER BY 
    C.Content_DatePublished ASC

Alternatively, you could GROUP BY the results

SELECT 
    C.Content_ID,
    C.Content_Title,
    C.Content_DatePublished,
    M.Media_Id
FROM 
    tbl_Contents C
    LEFT OUTER JOIN tbl_Media M ON M.Content_Id = C.Content_Id 
GROUP BY
    C.Content_ID,
    C.Content_Title,
    C.Content_DatePublished,
    M.Media_Id
ORDER BY
    C.Content_DatePublished ASC

The OUTER APPLY selects a single row (or none) that matches each row from the left table.

The GROUP BY performs the entire join, but then collapses the final result rows on the provided columns.

LinearLayout not expanding inside a ScrollView

I have dynamically used to get this . I have a LinearLayout and within this used ScrollView as a child. Then i take again LinearLayout and add what ever View u want to this LinearLayout and then this LinearLayout add to ScrollView and finally add this ScrollView to LinearLayout. Then u can get scroll in ur ScrollView and nothing will left to visible.

LinearLayout(Parent)--ScrollView(child of LinerLayout) -- LinearLayout(child of ScrollView)-- add here textView, Buttons , spinner etc whatever u want . Then add this LinearLyout to ScrollView. Bcoz only one CHILD for ScrollView applicable and last add this ScrollView to LinearLyout.If defined area is exceed from Screen size then u will get a Scroll within ScrollView.

How to delete/truncate tables from Hadoop-Hive?

You can use drop command to delete meta data and actual data from HDFS.

And just to delete data and keep the table structure, use truncate command.

For further help regarding hive ql, check language manual of hive.

Max size of an iOS application

As of July 2016:

Short Answer:

  1. If your game is released for iOS 9.0 or newer, you can have maximum app size of 400 MB for the size of the Mach-O binary file (for example, app_name.app/app_name).

  2. Your app’s total uncompressed size must be less than 4 Gb.


Long Answer:

Your app’s total uncompressed size must be less than 4 billion bytes. Each Mach-O executable file (for example, app_name.app/app_name) must not exceed these limits:

For apps whose MinimumOSVersion is less than 7.0: maximum of 80 MB for the total of all __TEXT sections in the binary.

For apps whose MinimumOSVersion is 7.x through 8.x: maximum of 60 MB per slice for the __TEXT section of each architecture slice in the binary.

For apps whose MinimumOSVersion is 9.0 or greater: maximum of 400 MB for the size of the Mach-O binary file.

However, consider download times when determining your app’s size. Minimize the file’s size as much as possible, keeping in mind that there is a 100 MB limit for over-the-air downloads. Abnormally large build files are usually the result of storing data, such as images, inside the compiled binary itself instead of as a resource inside your app bundle. If you are compiling an image or large dataset into your binary, it would be best to split this data out into a resource that is loaded dynamically by your app.


Here is the link to Apple Developer Guide that contains the info I posted above:

https://developer.apple.com/library/prerelease/content/documentation/LanguagesUtilities/Conceptual/iTunesConnect_Guide/Chapters/SubmittingTheApp.html

You can go to the section "Submitting the App for App Review" on the link above to read more on the info I posted above.

Allowing Java to use an untrusted certificate for SSL/HTTPS connection

Following code from here is a useful solution. No keystores etc. Just call method SSLUtilities.trustAllHttpsCertificates() before initializing the service and port (in SOAP).

import java.security.GeneralSecurityException;
import java.security.SecureRandom;
import java.security.cert.X509Certificate;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

/**
 * This class provide various static methods that relax X509 certificate and
 * hostname verification while using the SSL over the HTTP protocol.
 *  
 * @author Jiramot.info
 */
public final class SSLUtilities {

  /**
   * Hostname verifier for the Sun's deprecated API.
   *
   * @deprecated see {@link #_hostnameVerifier}.
   */
  private static com.sun.net.ssl.HostnameVerifier __hostnameVerifier;
  /**
   * Thrust managers for the Sun's deprecated API.
   *
   * @deprecated see {@link #_trustManagers}.
   */
  private static com.sun.net.ssl.TrustManager[] __trustManagers;
  /**
   * Hostname verifier.
   */
  private static HostnameVerifier _hostnameVerifier;
  /**
   * Thrust managers.
   */
  private static TrustManager[] _trustManagers;

  /**
   * Set the default Hostname Verifier to an instance of a fake class that
   * trust all hostnames. This method uses the old deprecated API from the
   * com.sun.ssl package.
   *  
   * @deprecated see {@link #_trustAllHostnames()}.
   */
  private static void __trustAllHostnames() {
    // Create a trust manager that does not validate certificate chains
    if (__hostnameVerifier == null) {
        __hostnameVerifier = new SSLUtilities._FakeHostnameVerifier();
    } // if
    // Install the all-trusting host name verifier
    com.sun.net.ssl.HttpsURLConnection
            .setDefaultHostnameVerifier(__hostnameVerifier);
  } // __trustAllHttpsCertificates

  /**
   * Set the default X509 Trust Manager to an instance of a fake class that
   * trust all certificates, even the self-signed ones. This method uses the
   * old deprecated API from the com.sun.ssl package.
   *
   * @deprecated see {@link #_trustAllHttpsCertificates()}.
   */
  private static void __trustAllHttpsCertificates() {
    com.sun.net.ssl.SSLContext context;

    // Create a trust manager that does not validate certificate chains
    if (__trustManagers == null) {
        __trustManagers = new com.sun.net.ssl.TrustManager[]{new SSLUtilities._FakeX509TrustManager()};
    } // if
    // Install the all-trusting trust manager
    try {
        context = com.sun.net.ssl.SSLContext.getInstance("SSL");
        context.init(null, __trustManagers, new SecureRandom());
    } catch (GeneralSecurityException gse) {
        throw new IllegalStateException(gse.getMessage());
    } // catch
    com.sun.net.ssl.HttpsURLConnection.setDefaultSSLSocketFactory(context
            .getSocketFactory());
  } // __trustAllHttpsCertificates

  /**
   * Return true if the protocol handler property java. protocol.handler.pkgs
   * is set to the Sun's com.sun.net.ssl. internal.www.protocol deprecated
   * one, false otherwise.
   *
   * @return true if the protocol handler property is set to the Sun's
   * deprecated one, false otherwise.
   */
  private static boolean isDeprecatedSSLProtocol() {
    return ("com.sun.net.ssl.internal.www.protocol".equals(System
            .getProperty("java.protocol.handler.pkgs")));
  } // isDeprecatedSSLProtocol

  /**
   * Set the default Hostname Verifier to an instance of a fake class that
   * trust all hostnames.
   */
  private static void _trustAllHostnames() {
      // Create a trust manager that does not validate certificate chains
      if (_hostnameVerifier == null) {
          _hostnameVerifier = new SSLUtilities.FakeHostnameVerifier();
      } // if
      // Install the all-trusting host name verifier:
      HttpsURLConnection.setDefaultHostnameVerifier(_hostnameVerifier);
  } // _trustAllHttpsCertificates

  /**
   * Set the default X509 Trust Manager to an instance of a fake class that
   * trust all certificates, even the self-signed ones.
   */
  private static void _trustAllHttpsCertificates() {
    SSLContext context;

      // Create a trust manager that does not validate certificate chains
      if (_trustManagers == null) {
          _trustManagers = new TrustManager[]{new SSLUtilities.FakeX509TrustManager()};
      } // if
      // Install the all-trusting trust manager:
      try {
          context = SSLContext.getInstance("SSL");
          context.init(null, _trustManagers, new SecureRandom());
      } catch (GeneralSecurityException gse) {
          throw new IllegalStateException(gse.getMessage());
      } // catch
      HttpsURLConnection.setDefaultSSLSocketFactory(context
            .getSocketFactory());
  } // _trustAllHttpsCertificates

  /**
   * Set the default Hostname Verifier to an instance of a fake class that
   * trust all hostnames.
   */
  public static void trustAllHostnames() {
      // Is the deprecated protocol setted?
      if (isDeprecatedSSLProtocol()) {
          __trustAllHostnames();
      } else {
          _trustAllHostnames();
      } // else
  } // trustAllHostnames

  /**
   * Set the default X509 Trust Manager to an instance of a fake class that
   * trust all certificates, even the self-signed ones.
   */
  public static void trustAllHttpsCertificates() {
    // Is the deprecated protocol setted?
    if (isDeprecatedSSLProtocol()) {
        __trustAllHttpsCertificates();
    } else {
        _trustAllHttpsCertificates();
    } // else
  } // trustAllHttpsCertificates

  /**
   * This class implements a fake hostname verificator, trusting any host
   * name. This class uses the old deprecated API from the com.sun. ssl
   * package.
   *
   * @author Jiramot.info
   *
   * @deprecated see {@link SSLUtilities.FakeHostnameVerifier}.
   */
  public static class _FakeHostnameVerifier implements
        com.sun.net.ssl.HostnameVerifier {

    /**
     * Always return true, indicating that the host name is an acceptable
     * match with the server's authentication scheme.
     *
     * @param hostname the host name.
     * @param session the SSL session used on the connection to host.
     * @return the true boolean value indicating the host name is trusted.
     */
    public boolean verify(String hostname, String session) {
        return (true);
    } // verify
  } // _FakeHostnameVerifier

  /**
   * This class allow any X509 certificates to be used to authenticate the
   * remote side of a secure socket, including self-signed certificates. This
   * class uses the old deprecated API from the com.sun.ssl package.
   *
   * @author Jiramot.info
   *
   * @deprecated see {@link SSLUtilities.FakeX509TrustManager}.
   */
  public static class _FakeX509TrustManager implements
        com.sun.net.ssl.X509TrustManager {

    /**
     * Empty array of certificate authority certificates.
     */
    private static final X509Certificate[] _AcceptedIssuers = new X509Certificate[]{};

    /**
     * Always return true, trusting for client SSL chain peer certificate
     * chain.
     *
     * @param chain the peer certificate chain.
     * @return the true boolean value indicating the chain is trusted.
     */
    public boolean isClientTrusted(X509Certificate[] chain) {
        return (true);
    } // checkClientTrusted

    /**
     * Always return true, trusting for server SSL chain peer certificate
     * chain.
     *
     * @param chain the peer certificate chain.
     * @return the true boolean value indicating the chain is trusted.
     */
    public boolean isServerTrusted(X509Certificate[] chain) {
        return (true);
    } // checkServerTrusted

    /**
     * Return an empty array of certificate authority certificates which are
     * trusted for authenticating peers.
     *
     * @return a empty array of issuer certificates.
     */
    public X509Certificate[] getAcceptedIssuers() {
        return (_AcceptedIssuers);
    } // getAcceptedIssuers
  } // _FakeX509TrustManager

  /**
   * This class implements a fake hostname verificator, trusting any host
   * name.
   *
   * @author Jiramot.info
   */
  public static class FakeHostnameVerifier implements HostnameVerifier {

    /**
     * Always return true, indicating that the host name is an acceptable
     * match with the server's authentication scheme.
     *
     * @param hostname the host name.
     * @param session the SSL session used on the connection to host.
     * @return the true boolean value indicating the host name is trusted.
     */
    public boolean verify(String hostname, javax.net.ssl.SSLSession session) {
        return (true);
    } // verify
  } // FakeHostnameVerifier

  /**
   * This class allow any X509 certificates to be used to authenticate the
   * remote side of a secure socket, including self-signed certificates.
   *
   * @author Jiramot.info
   */
  public static class FakeX509TrustManager implements X509TrustManager {

    /**
     * Empty array of certificate authority certificates.
     */
    private static final X509Certificate[] _AcceptedIssuers = new X509Certificate[]{};

    /**
     * Always trust for client SSL chain peer certificate chain with any
     * authType authentication types.
     *
     * @param chain the peer certificate chain.
     * @param authType the authentication type based on the client
     * certificate.
     */
    public void checkClientTrusted(X509Certificate[] chain, String authType) {
    } // checkClientTrusted

    /**
     * Always trust for server SSL chain peer certificate chain with any
     * authType exchange algorithm types.
     *
     * @param chain the peer certificate chain.
     * @param authType the key exchange algorithm used.
     */
    public void checkServerTrusted(X509Certificate[] chain, String authType) {
    } // checkServerTrusted

    /**
     * Return an empty array of certificate authority certificates which are
     * trusted for authenticating peers.
     *
     * @return a empty array of issuer certificates.
     */
    public X509Certificate[] getAcceptedIssuers() {
        return (_AcceptedIssuers);
    } // getAcceptedIssuers
  } // FakeX509TrustManager
} // SSLUtilities

How to check how many letters are in a string in java?

A)

String str = "a string";
int length = str.length( ); // length == 8

http://download.oracle.com/javase/7/docs/api/java/lang/String.html#length%28%29

edit

If you want to count the number of a specific type of characters in a String, then a simple method is to iterate through the String checking each index against your test case.

int charCount = 0;
char temp;

for( int i = 0; i < str.length( ); i++ )
{
    temp = str.charAt( i );

    if( temp.TestCase )
        charCount++;
}

where TestCase can be isLetter( ), isDigit( ), etc.

Or if you just want to count everything but spaces, then do a check in the if like temp != ' '

B)

String str = "a string";
char atPos0 = str.charAt( 0 ); // atPos0 == 'a'

http://download.oracle.com/javase/7/docs/api/java/lang/String.html#charAt%28int%29

How to implement LIMIT with SQL Server?

SELECT 
    * 
FROM 
    (
        SELECT 
            top 20              -- ($a) number of records to show
            * 
        FROM
            (
                SELECT 
                    top 29      -- ($b) last record position
                    * 
                FROM 
                    table       -- replace this for table name (i.e. "Customer")
                ORDER BY 
                    2 ASC
            ) AS tbl1 
        ORDER BY 
            2 DESC
    ) AS tbl2 
ORDER BY 
    2 ASC;

-- Examples:

-- Show 5 records from position 5:
-- $a = 5;
-- $b = (5 + 5) - 1
-- $b = 9;

-- Show 10 records from position 4:
-- $a = 10;
-- $b = (10 + 4) - 1
-- $b = 13;

-- To calculate $b:
-- $b = ($a + position) - 1

-- For the present exercise we need to:
-- Show 20 records from position 10:
-- $a = 20;
-- $b = (20 + 10) - 1
-- $b = 29;

Delaying AngularJS route change until model loaded to prevent flicker

I worked from Misko's code above and this is what I've done with it. This is a more current solution since $defer has been changed to $timeout. Substituting $timeout however will wait for the timeout period (in Misko's code, 1 second), then return the data hoping it's resolved in time. With this way, it returns asap.

function PhoneListCtrl($scope, phones) {
  $scope.phones = phones;
  $scope.orderProp = 'age';
}

PhoneListCtrl.resolve = {

  phones: function($q, Phone) {
    var deferred = $q.defer();

    Phone.query(function(phones) {
        deferred.resolve(phones);
    });

    return deferred.promise;
  }
}

Unbalanced calls to begin/end appearance transitions for <UITabBarController: 0x197870>

Without seeing more of the surrounding code I can't give a definite answer, but I have two theories.

  1. You're not using UIViewController's designated initializer initWithNibName:bundle:. Try using it instead of just init.

  2. Also, self may be one of the tab bar controller's view controllers. Always present view controllers from the topmost view controller, which means in this case ask the tab bar controller to present the overlay view controller on behalf of the view controller. You can still keep any callback delegates to the real view controller, but you must have the tab bar controller present and dismiss.

Using sed to split a string with a delimiter

Using \n in sed is non-portable. The portable way to do what you want with sed is:

sed 's/:/\
/g' ~/Desktop/myfile.txt

but in reality this isn't a job for sed anyway, it's the job tr was created to do:

tr ':' '
' < ~/Desktop/myfile.txt

Arduino COM port doesn't work

Abstract: Steps of How to resolve "Serial port 'COM1' not found" in fedora 17.

Today install the packages for Arduino in Fedora 17. (yum install arduino) and I have the same problem: I decided to upload an example to the chip. and got the same error "Serial port 'COM1' not found".

In this case when I run Arduino program, some banner appears which warns me that my user is not in 'dialout' and 'lock' group. Do you want add your user in this groups? I click in add button, but for some reason the program fail and not say nothing.

Step1: recognize the Arduino device unplug your Arduino and list /dev files:

#ls -l /dev

plug your Arduino and go and list /dev files

#ls -l /dev

Find the new file (device) that was not before plugging, for example:

ttyACM0 or ttyUSB1

Read this properties:

ls -l /dev/ttyACM0

crw-rw---- 1 root dialout 166, 0 Dec 24 19:25 /dev/ttyACM0

the first c mean that Arduino is a character device.

user owner: root

group owner: dialout

mayor number: 166

minor number: 0

Step2: set your user as group owner.

If you do:

groups <yourUser>

And you are not in 'dialout' and/or 'lock' group. Add yourself in this groups run as root:

usermod -aG lock <yourUser>
usermod -aG dialout <yourUser>

restart the pc, and set /dev/<yourDeviceFile> as your serial port before upload.

Enable tcp\ip remote connections to sql server express already installed database with code or script(query)

I tested below code with SQL Server 2008 R2 Express and I believe we should have solution for all 6 steps you outlined. Let's take on them one-by-one:

1 - Enable TCP/IP

We can enable TCP/IP protocol with WMI:

set wmiComputer = GetObject( _
    "winmgmts:" _
    & "\\.\root\Microsoft\SqlServer\ComputerManagement10")
set tcpProtocols = wmiComputer.ExecQuery( _
    "select * from ServerNetworkProtocol " _
    & "where InstanceName = 'SQLEXPRESS' and ProtocolName = 'Tcp'")

if tcpProtocols.Count = 1 then
    ' set tcpProtocol = tcpProtocols(0)
    ' I wish this worked, but unfortunately 
    ' there's no int-indexed Item property in this type

    ' Doing this instead
    for each tcpProtocol in tcpProtocols
        dim setEnableResult
            setEnableResult = tcpProtocol.SetEnable()
            if setEnableResult <> 0 then 
                Wscript.Echo "Failed!"
            end if
    next
end if

2 - Open the right ports in the firewall

I believe your solution will work, just make sure you specify the right port. I suggest we pick a different port than 1433 and make it a static port SQL Server Express will be listening on. I will be using 3456 in this post, but please pick a different number in the real implementation (I feel that we will see a lot of applications using 3456 soon :-)

3 - Modify TCP/IP properties enable a IP address

We can use WMI again. Since we are using static port 3456, we just need to update two properties in IPAll section: disable dynamic ports and set the listening port to 3456:

set wmiComputer = GetObject( _
    "winmgmts:" _
    & "\\.\root\Microsoft\SqlServer\ComputerManagement10")
set tcpProperties = wmiComputer.ExecQuery( _
    "select * from ServerNetworkProtocolProperty " _
    & "where InstanceName='SQLEXPRESS' and " _
    & "ProtocolName='Tcp' and IPAddressName='IPAll'")

for each tcpProperty in tcpProperties
    dim setValueResult, requestedValue

    if tcpProperty.PropertyName = "TcpPort" then
        requestedValue = "3456"
    elseif tcpProperty.PropertyName ="TcpDynamicPorts" then
        requestedValue = ""
    end if

    setValueResult = tcpProperty.SetStringValue(requestedValue)
    if setValueResult = 0 then 
        Wscript.Echo "" & tcpProperty.PropertyName & " set."
    else
        Wscript.Echo "" & tcpProperty.PropertyName & " failed!"
    end if
next

Note that I didn't have to enable any of the individual addresses to make it work, but if it is required in your case, you should be able to extend this script easily to do so.

Just a reminder that when working with WMI, WBEMTest.exe is your best friend!

4 - Enable mixed mode authentication in sql server

I wish we could use WMI again, but unfortunately this setting is not exposed through WMI. There are two other options:

  1. Use LoginMode property of Microsoft.SqlServer.Management.Smo.Server class, as described here.

  2. Use LoginMode value in SQL Server registry, as described in this post. Note that by default the SQL Server Express instance is named SQLEXPRESS, so for my SQL Server 2008 R2 Express instance the right registry key was HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10_50.SQLEXPRESS\MSSQLServer.

5 - Change user (sa) default password

You got this one covered.

6 - Finally (connect to the instance)

Since we are using a static port assigned to our SQL Server Express instance, there's no need to use instance name in the server address anymore.

SQLCMD -U sa -P newPassword -S 192.168.0.120,3456

Please let me know if this works for you (fingers crossed!).

How do shift operators work in Java?

2 from decimal numbering system in binary is as follows

10

now if you do

2 << 11

it would be , 11 zeros would be padded on the right side

1000000000000

The signed left shift operator "<<" shifts a bit pattern to the left, and the signed right shift operator ">>" shifts a bit pattern to the right. The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator ">>>" shifts a zero into the leftmost position, while the leftmost position after ">>" depends on sign extension [..]

left shifting results in multiplication by 2 (*2) in terms or arithmetic


For example

2 in binary 10, if you do <<1 that would be 100 which is 4

4 in binary 100, if you do <<1 that would be 1000 which is 8


Also See

What's the point of the X-Requested-With header?

A good reason is for security - this can prevent CSRF attacks because this header cannot be added to the AJAX request cross domain without the consent of the server via CORS.

Only the following headers are allowed cross domain:

  • Accept
  • Accept-Language
  • Content-Language
  • Last-Event-ID
  • Content-Type

any others cause a "pre-flight" request to be issued in CORS supported browsers.

Without CORS it is not possible to add X-Requested-With to a cross domain XHR request.

If the server is checking that this header is present, it knows that the request didn't initiate from an attacker's domain attempting to make a request on behalf of the user with JavaScript. This also checks that the request wasn't POSTed from a regular HTML form, of which it is harder to verify it is not cross domain without the use of tokens. (However, checking the Origin header could be an option in supported browsers, although you will leave old browsers vulnerable.)

New Flash bypass discovered

You may wish to combine this with a token, because Flash running on Safari on OSX can set this header if there's a redirect step. It appears it also worked on Chrome, but is now remediated. More details here including different versions affected.

OWASP Recommend combining this with an Origin and Referer check:

This defense technique is specifically discussed in section 4.3 of Robust Defenses for Cross-Site Request Forgery. However, bypasses of this defense using Flash were documented as early as 2008 and again as recently as 2015 by Mathias Karlsson to exploit a CSRF flaw in Vimeo. But, we believe that the Flash attack can't spoof the Origin or Referer headers so by checking both of them we believe this combination of checks should prevent Flash bypass CSRF attacks. (NOTE: If anyone can confirm or refute this belief, please let us know so we can update this article)

However, for the reasons already discussed checking Origin can be tricky.

Update

Written a more in depth blog post on CORS, CSRF and X-Requested-With here.

How to hide/show more text within a certain length (like youtube)

For those who just want a simple Bootstrap solution.

    <style>
     .collapse.in { display: inline !important; }
    </style>

    Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the
    <span class="collapse" id="more">
      1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.
    </span>
    <span><a href="#more" data-toggle="collapse">... <i class="fa fa-caret-down"></i></span>

Here's a CodePen example.

Remember to include jquery and bootstrap.min.js in your header.

If you aren't using fontawesome icons, change <i class="fa fa-caret-down"></i> to any icon of your choice.

else & elif statements not working in Python

indentation is important in Python. Your if else statement should be within triple arrow (>>>), In Mac python IDLE version 3.7.4 elif statement doesn't comes with correct indentation when you go on next line you have to shift left to avoid syntax error.

enter image description here

Removing legend on charts with chart.js v2

The options object can be added to the chart when the new Chart object is created.

var chart1 = new Chart(canvas, {
    type: "pie",
    data: data,
    options: {
         legend: {
            display: false
         },
         tooltips: {
            enabled: false
         }
    }
});

How to use andWhere and orWhere in Doctrine?

Here's an example for those who have more complicated conditions and using Doctrine 2.* with QueryBuilder:

$qb->where('o.foo = 1')
   ->andWhere($qb->expr()->orX(
      $qb->expr()->eq('o.bar', 1),
      $qb->expr()->eq('o.bar', 2)
   ))
  ;

Those are expressions mentioned in Czechnology answer.

How to scroll to an element in jQuery?

Like @user293153 I only just discovered this question and it didn't seem to be answered correctly.

His answer was best. But you can also animate to the element as well.

$('html, body').animate({ scrollTop: $("#some_element").offset().top }, 500);

Resetting a setTimeout

To reset the timer, you would need to set and clear out the timer variable

$time_out_handle = 0;
window.clearTimeout($time_out_handle);
$time_out_handle = window.setTimeout( function(){---}, 60000 );

The EntityManager is closed

// first need to reset current manager
$em->resetManager();
// and then get new
$em = $this->getContainer()->get("doctrine");
// or in this way, depending of your environment:
$em = $this->getDoctrine();

Are arrays in PHP copied as value or as reference to new variables, and when passed to functions?

TL;DR

a) the method/function only reads the array argument => implicit (internal) reference
b) the method/function modifies the array argument => value
c) the method/function array argument is explicitly marked as a reference (with an ampersand) => explicit (user-land) reference

Or this:
- non-ampersand array param: passed by reference; the writing operations alter a new copy of the array, copy which is created on the first write;
- ampersand array param: passed by reference; the writing operations alter the original array.

Remember - PHP does a value-copy the moment you write to the non-ampersand array param. That's what copy-on-write means. I'd love to show you the C source of this behaviour, but it's scary in there. Better use xdebug_debug_zval().

Pascal MARTIN was right. Kosta Kontos was even more so.

Answer

It depends.

Long version

I think I'm writing this down for myself. I should have a blog or something...

Whenever people talk of references (or pointers, for that matter), they usually end up in a logomachy (just look at this thread!).
PHP being a venerable language, I thought I should add up to the confusion (even though this a summary of the above answers). Because, although two people can be right at the same time, you're better off just cracking their heads together into one answer.

First off, you should know that you're not a pedant if you don't answer in a black-and-white manner. Things are more complicated than "yes/no".

As you will see, the whole by-value/by-reference thing is very much related to what exactly are you doing with that array in your method/function scope: reading it or modifying it?

What does PHP says? (aka "change-wise")

The manual says this (emphasis mine):

By default, function arguments are passed by value (so that if the value of the argument within the function is changed, it does not get changed outside of the function). To allow a function to modify its arguments, they must be passed by reference.

To have an argument to a function always passed by reference, prepend an ampersand (&) to the argument name in the function definition

As far as I can tell, when big, serious, honest-to-God programmers talk about references, they usually talk about altering the value of that reference. And that's exactly what the manual talks about: hey, if you want to CHANGE the value in a function, consider that PHP's doing "pass-by-value".

There's another case that they don't mention, though: what if I don't change anything - just read?
What if you pass an array to a method which doesn't explicitly marks a reference, and we don't change that array in the function scope? E.g.:

<?php
function readAndDoStuffWithAnArray($array) 
{
    return $array[0] + $array[1] + $array[2];
}

$x = array(1, 2, 3);

echo readAndDoStuffWithAnArray($x);

Read on, my fellow traveller.

What does PHP actually do? (aka "memory-wise")

The same big and serious programmers, when they get even more serious, they talk about "memory optimizations" in regards to references. So does PHP. Because PHP is a dynamic, loosely typed language, that uses copy-on-write and reference counting, that's why.

It wouldn't be ideal to pass HUGE arrays to various functions, and PHP to make copies of them (that's what "pass-by-value" does, after all):

<?php

// filling an array with 10000 elements of int 1
// let's say it grabs 3 mb from your RAM
$x = array_fill(0, 10000, 1); 

// pass by value, right? RIGHT?
function readArray($arr) { // <-- a new symbol (variable) gets created here
    echo count($arr); // let's just read the array
}

readArray($x);

Well now, if this actually was pass-by-value, we'd have some 3mb+ RAM gone, because there are two copies of that array, right?

Wrong. As long as we don't change the $arr variable, that's a reference, memory-wise. You just don't see it. That's why PHP mentions user-land references when talking about &$someVar, to distinguish between internal and explicit (with ampersand) ones.

Facts

So, when an array is passed as an argument to a method or function is it passed by reference?

I came up with three (yeah, three) cases:
a) the method/function only reads the array argument
b) the method/function modifies the array argument
c) the method/function array argument is explicitly marked as a reference (with an ampersand)


Firstly, let's see how much memory that array actually eats (run here):

<?php
$start_memory = memory_get_usage();
$x = array_fill(0, 10000, 1);
echo memory_get_usage() - $start_memory; // 1331840

That many bytes. Great.

a) the method/function only reads the array argument

Now let's make a function which only reads the said array as an argument and we'll see how much memory the reading logic takes:

<?php

function printUsedMemory($arr) 
{
    $start_memory = memory_get_usage();

    count($arr);       // read
    $x = $arr[0];      // read (+ minor assignment)
    $arr[0] - $arr[1]; // read

    echo memory_get_usage() - $start_memory; // let's see the memory used whilst reading
}

$x = array_fill(0, 10000, 1); // this is 1331840 bytes
printUsedMemory($x);

Wanna guess? I get 80! See for yourself. This is the part that the PHP manual omits. If the $arr param was actually passed-by-value, you'd see something similar to 1331840 bytes. It seems that $arr behaves like a reference, doesn't it? That's because it is a references - an internal one.

b) the method/function modifies the array argument

Now, let's write to that param, instead of reading from it:

<?php

function printUsedMemory($arr)
{
    $start_memory = memory_get_usage();

    $arr[0] = 1; // WRITE!

    echo memory_get_usage() - $start_memory; // let's see the memory used whilst reading
}

$x = array_fill(0, 10000, 1);
printUsedMemory($x);

Again, see for yourself, but, for me, that's pretty close to being 1331840. So in this case, the array is actually being copied to $arr.

c) the method/function array argument is explicitly marked as a reference (with an ampersand)

Now let's see how much memory a write operation to an explicit reference takes (run here) - note the ampersand in the function signature:

<?php

function printUsedMemory(&$arr) // <----- explicit, user-land, pass-by-reference
{
    $start_memory = memory_get_usage();

    $arr[0] = 1; // WRITE!

    echo memory_get_usage() - $start_memory; // let's see the memory used whilst reading
}

$x = array_fill(0, 10000, 1);
printUsedMemory($x);

My bet is that you get 200 max! So this eats approximately as much memory as reading from a non-ampersand param.

Excel "External table is not in the expected format."

This can also be a file that contains images or charts, see this: http://kb.tableausoftware.com/articles/knowledgebase/resolving-error-external-table-is-not-in-expected-format

The recommendation is to save as Excel 2003

Creating a div element inside a div element in javascript

Yes, you either need to do this onload or in a <script> tag after the closing </body> tag, when the lc element is already found in the document's DOM tree.

What is android:weightSum in android, and how does it work?

If unspecified, the sum is computed by adding the layout_weight of all of the children. This can be used for instance to give a single child 50% of the total available space by giving it a layout_weight of 0.5 and setting the weightSum to 1.0. Must be a floating point value, such as "1.2"

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/main_rel"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:weightSum="2.0" >

        <RelativeLayout
            android:id="@+id/child_one"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1.0"
            android:background="#0000FF" >
        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/child_two"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1.0"
            android:background="#00FF00" >
        </RelativeLayout>

    </LinearLayout>

Dynamically add data to a javascript map

Well any Javascript object functions sort-of like a "map"

randomObject['hello'] = 'world';

Typically people build simple objects for the purpose:

var myMap = {};

// ...

myMap[newKey] = newValue;

edit — well the problem with having an explicit "put" function is that you'd then have to go to pains to avoid having the function itself look like part of the map. It's not really a Javascripty thing to do.

13 Feb 2014 — modern JavaScript has facilities for creating object properties that aren't enumerable, and it's pretty easy to do. However, it's still the case that a "put" property, enumerable or not, would claim the property name "put" and make it unavailable. That is, there's still only one namespace per object.

How would I extract a single file (or changes to a file) from a git stash?

Use the following to apply the changes to a file in a stash to your working tree.

git diff stash^! -- <filename> | git apply

This is generally better than using git checkout because you won't lose any changes you made to file since you created the stash.

Open a new tab in the background?

UPDATE: By version 41 of Google Chrome, initMouseEvent seemed to have a changed behavior.

this can be done by simulating ctrl + click (or any other key/event combinations that open a background tab) on a dynamically generated a element with its href attribute set to the desired url

In action: fiddle

function openNewBackgroundTab(){
    var a = document.createElement("a");
    a.href = "http://www.google.com/";
    var evt = document.createEvent("MouseEvents");
    //the tenth parameter of initMouseEvent sets ctrl key
    evt.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0,
                                true, false, false, false, 0, null);
    a.dispatchEvent(evt);
}

tested only on chrome

Find control by name from Windows Forms controls

TextBox tbx = this.Controls.Find("textBox1", true).FirstOrDefault() as TextBox;
tbx.Text = "found!";

If Controls.Find is not found "textBox1" => error. You must add code.

If(tbx != null)

Edit:

TextBox tbx = this.Controls.Find("textBox1", true).FirstOrDefault() as TextBox;
If(tbx != null)
   tbx.Text = "found!";

Javascript counting number of objects in object

The easiest way to do this, with excellent performance and compatibility with both old and new browsers, is to include either Lo-Dash or Underscore in your page.

Then you can use either _.size(object) or _.keys(object).length

For your obj.Data, you could test this with:

console.log( _.size(obj.Data) );

or:

console.log( _.keys(obj.Data).length );

Lo-Dash and Underscore are both excellent libraries; you would find either one very useful in your code. (They are rather similar to each other; Lo-Dash is a newer version with some advantanges.)

Alternatively, you could include this function in your code, which simply loops through the object's properties and counts them:

function ObjectLength( object ) {
    var length = 0;
    for( var key in object ) {
        if( object.hasOwnProperty(key) ) {
            ++length;
        }
    }
    return length;
};

You can test this with:

console.log( ObjectLength(obj.Data) );

That code is not as fast as it could be in modern browsers, though. For a version that's much faster in modern browsers and still works in old ones, you can use:

function ObjectLength_Modern( object ) {
    return Object.keys(object).length;
}

function ObjectLength_Legacy( object ) {
    var length = 0;
    for( var key in object ) {
        if( object.hasOwnProperty(key) ) {
            ++length;
        }
    }
    return length;
}

var ObjectLength =
    Object.keys ? ObjectLength_Modern : ObjectLength_Legacy;

and as before, test it with:

console.log( ObjectLength(obj.Data) );

This code uses Object.keys(object).length in modern browsers and falls back to counting in a loop for old browsers.

But if you're going to all this work, I would recommend using Lo-Dash or Underscore instead and get all the benefits those libraries offer.

I set up a jsPerf that compares the speed of these various approaches. Please run it in any browsers you have handy to add to the tests.

Thanks to Barmar for suggesting Object.keys for newer browsers in his answer.

Run react-native on android emulator

In my case, this was happening because the android/gradlew file did not have execute permission. Once granted, this worked fine

Does MySQL ignore null values on unique constraints?

Yes, MySQL allows multiple NULLs in a column with a unique constraint.

CREATE TABLE table1 (x INT NULL UNIQUE);
INSERT table1 VALUES (1);
INSERT table1 VALUES (1);   -- Duplicate entry '1' for key 'x'
INSERT table1 VALUES (NULL);
INSERT table1 VALUES (NULL);
SELECT * FROM table1;

Result:

x
NULL
NULL
1

This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.

Copy Paste Values only( xlPasteValues )

since you only want values copied, you can pass the values of arr1 directly to arr2 and avoid copy/paste. code inside the loop:

      Sheets("SheetB").Range(arr2(i) & firstrowDB).Resize(lastrow, 1).Value = .Range(.Cells(1, arr1(i)), .Cells(lastrow, arr1(i))).Value

Check if value exists in dataTable?

DataRow rw = table.AsEnumerable().FirstOrDefault(tt => tt.Field<string>("Author") == "Name");
if (rw != null)
{
// row exists
}

add to your using clause :

using System.Linq;

and add :

System.Data.DataSetExtensions

to references.

Prevent textbox autofill with previously entered values

Please note that for Chrome to work properly it needs to be autocomplete="false"

how I can show the sum of in a datagridview column?

Fast and clean way using LINQ

int total = dataGridView1.Rows.Cast<DataGridViewRow>()
                .Sum(t => Convert.ToInt32(t.Cells[1].Value));

verified on VS2013

How to generate Javadoc HTML files in Eclipse?

To quickly add a Javadoc use following shortcut:

Windows: alt + shift + J

Mac: ? + Alt + J

Depending on selected context, a Javadoc will be printed. To create Javadoc written by OP, select corresponding method and hit the shotcut keys.

How to create an 2D ArrayList in java?

The best way is to use a List within a List:

List<List<String>> listOfLists = new ArrayList<List<String>>();  

How can I reference a commit in an issue comment on GitHub?

Answer above is missing an example which might not be obvious (it wasn't to me).

Url could be broken down into parts

https://github.com/liufa/Tuplinator/commit/f36e3c5b3aba23a6c9cf7c01e7485028a23c3811
                  \_____/\________/       \_______________________________________/
                   |        |                              |
            Account name    |                      Hash of revision
                        Project name              

Hash can be found here (you can click it and will get the url from browser).

enter image description here

Hope this saves you some time.

What is the difference between HTML tags <div> and <span>?

Remember, basically and them self doesn't perform any function either. They are not specific about functionality just by their tags.

They can only be customized with the help of CSS.

Now that coming to your question:

SPAN tag together with some styling will be useful on having hold inside a line, say in a paragraph, in the html. This is kind of line level or statement level in HTML.

Example:

<p>Am writing<span class="time">this answer</span> in my free time of my day.</p>

DIV tag functionality as said can only be visible backed with styling, can have hold of large chunks of HTML code.

DIV is Block level

Example:

    <div class="large-time">
    <p>Am writing <span class="time"> this answer</span> in my free time of my day. 
    </p>
    </div>

Both have their time and case when to be used, based on your requirement.

Hope am clear with the answer. Thank you.

How to get current class name including package name in Java?

use this.getClass().getName() to get packageName.className and use this.getClass().getSimpleName() to get only class name

What does "The APR based Apache Tomcat Native library was not found" mean?

Installation the native library on Ubuntu server with:

sudo apt-get install libtcnative-1

If that does not work tomcat-native needs to be installed

  1. Install Oracle java7:

    • sudo add-apt-repository ppa:webupd8team/java
    • sudo apt-get update
    • sudo apt-get install oracle-java7-installer
    • sudo apt-get install oracle-java7-set-default
  2. Install tomcat apr:

  3. Install tomcat tomcat-native:

Passing route control with optional parameter after root in express?

That would work depending on what client.get does when passed undefined as its first parameter.

Something like this would be safer:

app.get('/:key?', function(req, res, next) {
    var key = req.params.key;
    if (!key) {
        next();
        return;
    }
    client.get(key, function(err, reply) {
        if(client.get(reply)) {
            res.redirect(reply);
        }
        else {
            res.render('index', {
                link: null
            });
        }
    });
});

There's no problem in calling next() inside the callback.

According to this, handlers are invoked in the order that they are added, so as long as your next route is app.get('/', ...) it will be called if there is no key.

In which case do you use the JPA @JoinTable annotation?

It's the only solution to map a ManyToMany association : you need a join table between the two entities tables to map the association.

It's also used for OneToMany (usually unidirectional) associations when you don't want to add a foreign key in the table of the many side and thus keep it independent of the one side.

Search for @JoinTable in the hibernate documentation for explanations and examples.

How do I put the image on the right side of the text in a UIButton?

Being that the transform solution doesn't work in iOS 11 I decided to write a new approach.

Adjusting the buttons semanticContentAttribute gives us the image nicely to the right without having to relayout if the text changes. Because of this it's the ideal solution. However I still need RTL support. The fact that an app can not change it's layout direction in the same session resolves this issue easily.

With that said, it's pretty straight forward.

extension UIButton {
    func alignImageRight() {
        if UIApplication.shared.userInterfaceLayoutDirection == .leftToRight {
            semanticContentAttribute = .forceRightToLeft
        }
        else {
            semanticContentAttribute = .forceLeftToRight
        }
    }
}

How to export dataGridView data Instantly to Excel on button click?

Interop is slow and has other issues, using the the clipboard seems non extensible. Here are two other ways to do this

  1. Work with Excel 2007+ files directly instead of working with Excel, it'll be much (much) faster. You can use OpenXML (http://openxmldeveloper.org/) which is Microsoft's SDK. The best way to learn OpenXML is to download the Productivity tool (http://www.microsoft.com/en-us/download/details.aspx?id=5124), ittakes an existing file and generates the code required to create it. Another, perhaps simpler, option is to use ClosedXML (http://closedxml.codeplex.com/). It seems a lot easier to use (look at the example http://closedxml.codeplex.com/wikipage?title=Showcase&referringTitle=Home), but I have no experience with it. I'm sure there are other libraries that wrap work with Excel.

  2. Work with excel via OLEDB. This allows you to work with Excel as if it's a dababase. See http://www.codeproject.com/Articles/8500/Reading-and-Writing-Excel-using-OLEDB or Performance of OLEDB to read Excel for examples and more details.

I'd start with ClosedXML.

Replacing backslashes with forward slashes with str_replace() in php

Single quoted php string variable works.

$str = 'http://www.domain.com/data/images\flags/en.gif';
$str = str_replace('\\', '/', $str);

How can I populate a select dropdown list from a JSON feed with AngularJS?

<select name="selectedFacilityId" ng-model="selectedFacilityId">
         <option ng-repeat="facility in facilities" value="{{facility.id}}">{{facility.name}}</option>
     </select>  

This is an example on how to use it.

How can I enter latitude and longitude in Google Maps?

First is latitude, second longitude. Different than many constructors in mapbox.

Here are examples of formats that work:

  • Degrees, minutes, and seconds (DMS): 41°24'12.2"N 2°10'26.5"E
  • Degrees and decimal minutes (DMM): 41 24.2028, 2 10.4418
  • Decimal degrees (DD): 41.40338, 2.17403

Tips for formatting your coordinates

  • Use the degree symbol instead of “d”.
  • Use periods as decimals, not commas.
    • Incorrect: 41,40338, 2,17403.
    • Correct: 41.40338, 2.17403.
  • List your latitude coordinates before longitude coordinates.
  • Check that the first number in your latitude coordinate is between -90 and 90 and the first number in your longitude coordinate is between -180 and 180.

https://support.google.com/maps/answer/18539

Spring JPA @Query with LIKE

@Query("select u from user u where u.username LIKE :username")
List<User> findUserByUsernameLike(@Param("username") String username);

Is there a foreach loop in Go?

I have jus implement this library:https://github.com/jose78/go-collection. This is an example about how to use the Foreach loop:

package main

import (
    "fmt"

    col "github.com/jose78/go-collection/collections"
)

type user struct {
    name string
    age  int
    id   int
}

func main() {
    newList := col.ListType{user{"Alvaro", 6, 1}, user{"Sofia", 3, 2}}
    newList = append(newList, user{"Mon", 0, 3})

    newList.Foreach(simpleLoop)
    
    if err := newList.Foreach(simpleLoopWithError); err != nil{
        fmt.Printf("This error >>> %v <<< was produced", err )  
    }
}

var simpleLoop col.FnForeachList = func(mapper interface{}, index int) {
    fmt.Printf("%d.- item:%v\n", index, mapper)
}


var simpleLoopWithError col.FnForeachList = func(mapper interface{}, index int) {
    if index > 1{
        panic(fmt.Sprintf("Error produced with index == %d\n", index))
    }
    fmt.Printf("%d.- item:%v\n", index, mapper)
}

The result of this execution should be:

0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
2.- item:{Mon 0 3}
0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
Recovered in f Error produced with index == 2

ERROR: Error produced with index == 2
This error >>> Error produced with index == 2
 <<< was produced

Try this code in playGrounD

Create instance of generic type whose constructor requires a parameter?

You can do by using reflection:

public void AddFruit<T>()where T: BaseFruit
{
  ConstructorInfo constructor = typeof(T).GetConstructor(new Type[] { typeof(int) });
  if (constructor == null)
  {
    throw new InvalidOperationException("Type " + typeof(T).Name + " does not contain an appropriate constructor");
  }
  BaseFruit fruit = constructor.Invoke(new object[] { (int)150 }) as BaseFruit;
  fruit.Enlist(fruitManager);
}

EDIT: Added constructor == null check.

EDIT: A faster variant using a cache:

public void AddFruit<T>()where T: BaseFruit
{
  var constructor = FruitCompany<T>.constructor;
  if (constructor == null)
  {
    throw new InvalidOperationException("Type " + typeof(T).Name + " does not contain an appropriate constructor");
  }
  var fruit = constructor.Invoke(new object[] { (int)150 }) as BaseFruit;
  fruit.Enlist(fruitManager);
}
private static class FruitCompany<T>
{
  public static readonly ConstructorInfo constructor = typeof(T).GetConstructor(new Type[] { typeof(int) });
}

Uncaught TypeError: Cannot read property 'length' of undefined

You are accessing an object that is not defined.

The solution is check for null or undefined (to see whether the object exists) and only then iterate.

Any way to exit bash script, but not quitting the terminal

It's correct that sourced vs. executed scripts use return vs. exit to keep the same session open, as others have noted.

Here's a related tip, if you ever want a script that should keep the session open, regardless of whether or not it's sourced.

The following example can be run directly like foo.sh or sourced like . foo.sh/source foo.sh. Either way it will keep the session open after "exiting". The $@ string is passed so that the function has access to the outer script's arguments.

#!/bin/sh
foo(){
    read -p "Would you like to XYZ? (Y/N): " response;
    [ $response != 'y' ] && return 1;
    echo "XYZ complete (args $@).";
    return 0;
    echo "This line will never execute.";
}
foo "$@";

Terminal result:

$ foo.sh
$ Would you like to XYZ? (Y/N): n
$ . foo.sh
$ Would you like to XYZ? (Y/N): n
$ |
(terminal window stays open and accepts additional input)

This can be useful for quickly testing script changes in a single terminal while keeping a bunch of scrap code underneath the main exit/return while you work. It could also make code more portable in a sense (if you have tons of scripts that may or may not be called in different ways), though it's much less clunky to just use return and exit where appropriate.

What does 'URI has an authority component' mean?

An authority is a portion of a URI. Your error suggests that it was not expecting one. The authority section is shown below, it is what is known as the website part of the url.

From RFC3986 on URIs:

The following is an example URI and its component parts:

     foo://example.com:8042/over/there?name=ferret#nose
     \_/   \______________/\_________/ \_________/ \__/
      |           |            |            |        |
   scheme     authority       path        query   fragment
      |   _____________________|__
     / \ /                        \
     urn:example:animal:ferret:nose

So there are two formats, one with an authority and one not. Regarding slashes:

"When authority is not present, the path cannot begin with two slash
characters ("//")."

Source: https://tools.ietf.org/rfc/rfc3986.txt (search for text 'authority is not present, the path cannot begin with two slash')

Extracting just Month and Year separately from Pandas Datetime column

There is two steps to extract year for all the dataframe without using method apply.

Step1

convert the column to datetime :

df['ArrivalDate']=pd.to_datetime(df['ArrivalDate'], format='%Y-%m-%d')

Step2

extract the year or the month using DatetimeIndex() method

 pd.DatetimeIndex(df['ArrivalDate']).year

Checkout old commit and make it a new commit

The other answers so far create new commits that undo what is in older commits. It is possible to go back and "change history" as it were, but this can be a bit dangerous. You should only do this if the commit you're changing has not been pushed to other repositories.

The command you're looking for is git rebase --interactive

If you want to change HEAD~3, the command you want to issue is git rebase --interactive HEAD~4. This will open a text editor and allow you to specify which commits you want to change.

Practice on a different repository before you try this with something important. The man pages should give you all the rest of the information you need.

How to read/write files in .Net Core?

To write:

using (System.IO.StreamWriter file =
new System.IO.StreamWriter(System.IO.File.Create(filePath).Dispose()))
{
    file.WriteLine("your text here");
}

ASP.NET Core Dependency Injection error: Unable to resolve service for type while attempting to activate

ohh, Thank @kimbaudi, i followed this tuts

https://dotnettutorials.net/lesson/generic-repository-pattern-csharp-mvc/

and got the same error as your. But after read your code i found out my solution was adding

services.AddScoped(IGenericRepository, GenericRepository);

into ConfigureServices method in StartUp.cs file =))

How to convert numbers between hexadecimal and decimal

My solution is a bit like back to basics, but it works without using any built-in functions to convert between number systems.

    public static string DecToHex(long a)
    {
        int n = 1;
        long b = a;
        while (b > 15)
        {
            b /= 16;
            n++;
        }
        string[] t = new string[n];
        int i = 0, j = n - 1;
        do
        {
                 if (a % 16 == 10) t[i] = "A";
            else if (a % 16 == 11) t[i] = "B";
            else if (a % 16 == 12) t[i] = "C";
            else if (a % 16 == 13) t[i] = "D";
            else if (a % 16 == 14) t[i] = "E";
            else if (a % 16 == 15) t[i] = "F";
            else t[i] = (a % 16).ToString();
            a /= 16;
            i++;
        }
        while ((a * 16) > 15);
        string[] r = new string[n];
        for (i = 0; i < n; i++)
        {
            r[i] = t[j];
            j--;
        }
        string res = string.Concat(r);
        return res;
    }

api-ms-win-crt-runtime-l1-1-0.dll is missing when opening Microsoft Office file

if anybody unable to update windows online, I suggest you go to http://download.wsusoffline.net/ and download Most recent version.

Then install update generator -> select your operating system. and hit START, just wait few minutes let him download updates and complete all it's process. hope this help.

Image of Offline update generator

How to delete directory content in Java?

You can't delete on an array ! This should work better :

for (File f : files) f.delete();

But it won't work if the folders are not empty. For this cases, you will need to recursively descend into the folder hierarchy and delete everything. Yes it's a shame Java can't do that by default...

jQuery selectors on custom data attributes using HTML5

jsFiddle Demo

jQuery provides several selectors (full list) in order to make the queries you are looking for work. To address your question "In other cases is it possible to use other selectors like "contains, less than, greater than, etc..."." you can also use contains, starts with, and ends with to look at these html5 data attributes. See the full list above in order to see all of your options.

The basic querying has been covered above, and using John Hartsock's answer is going to be the best bet to either get every data-company element, or to get every one except Microsoft (or any other version of :not).

In order to expand this to the other points you are looking for, we can use several meta selectors. First, if you are going to do multiple queries, it is nice to cache the parent selection.

var group = $('ul[data-group="Companies"]');

Next, we can look for companies in this set who start with G

var google = $('[data-company^="G"]',group);//google

Or perhaps companies which contain the word soft

var microsoft = $('[data-company*="soft"]',group);//microsoft

It is also possible to get elements whose data attribute's ending matches

var facebook = $('[data-company$="book"]',group);//facebook

_x000D_
_x000D_
//stored selector_x000D_
var group = $('ul[data-group="Companies"]');_x000D_
_x000D_
//data-company starts with G_x000D_
var google = $('[data-company^="G"]',group).css('color','green');_x000D_
_x000D_
//data-company contains soft_x000D_
var microsoft = $('[data-company*="soft"]',group).css('color','blue');_x000D_
_x000D_
//data-company ends with book_x000D_
var facebook = $('[data-company$="book"]',group).css('color','pink');
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<ul data-group="Companies">_x000D_
  <li data-company="Microsoft">Microsoft</li>_x000D_
  <li data-company="Google">Google</li>_x000D_
  <li data-company ="Facebook">Facebook</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

How to redirect to another page using PHP

On click BUTTON action

   if(isset($_POST['save_btn']))
    {
        //write some of your code here, if necessary
        echo'<script> window.location="B.php"; </script> ';
     }

Are members of a C++ struct initialized to 0 by default?

Move pod members to a base class to shorten your initializer list:

struct foo_pod
{
    int x;
    int y;
    int z;
};

struct foo : foo_pod
{
    std::string name;
    foo(std::string name)
        : foo_pod()
        , name(name)
    {
    }
};

int main()
{
    foo f("bar");
    printf("%d %d %d %s\n", f.x, f.y, f.z, f.name.c_str());
}

Inserting data to table (mysqli insert)

Okay, of course the question has been answered, but no-one seems to notice the third line of your code. It continuosly bugged me.

    <?php
    mysqli_connect("localhost","root","","web_table");
    mysql_select_db("web_table") or die(mysql_error());

for some reason, you made a mysqli connection to server, but you are trying to make a mysql connection to database.To get going, rather use

       $link = mysqli_connect("localhost","root","","web_table");
       mysqli_select_db ($link , "web_table" ) or die.....

or for where i began

     <?php $connection = mysqli_connect("localhost","root","","web_table");       
      global $connection; // global connection to databases - kill it once you're done

or just query with a $connection parameter as the other argument like above. Get rid of that third line.

Using AES encryption in C#

Using AES or implementing AES? To use AES, there is the System.Security.Cryptography.RijndaelManaged class.

Postgres integer arrays as parameters?

See: http://www.postgresql.org/docs/9.1/static/arrays.html

If your non-native driver still does not allow you to pass arrays, then you can:

  • pass a string representation of an array (which your stored procedure can then parse into an array -- see string_to_array)

    CREATE FUNCTION my_method(TEXT) RETURNS VOID AS $$ 
    DECLARE
           ids INT[];
    BEGIN
           ids = string_to_array($1,',');
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method(:1)
    

    with :1 = '1,2,3,4'

  • rely on Postgres itself to cast from a string to an array

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method('{1,2,3,4}')
    
  • choose not to use bind variables and issue an explicit command string with all parameters spelled out instead (make sure to validate or escape all parameters coming from outside to avoid SQL injection attacks.)

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method(ARRAY [1,2,3,4])
    

How to Rotate a UIImage 90 degrees?

If you want to add a photo rotate button that'll keep rotating the photo in 90 degree increments, here you go. (finalImage is a UIImage that's already been created elsewhere.)

- (void)rotatePhoto {
    UIImage *rotatedImage;

    if (finalImage.imageOrientation == UIImageOrientationRight)
        rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
                                              scale: 1.0
                                        orientation: UIImageOrientationDown];
    else if (finalImage.imageOrientation == UIImageOrientationDown)
        rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
                                              scale: 1.0
                                        orientation: UIImageOrientationLeft];
    else if (finalImage.imageOrientation == UIImageOrientationLeft)
        rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
                                              scale: 1.0
                                        orientation: UIImageOrientationUp];
    else
        rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
                                                     scale: 1.0
                                               orientation: UIImageOrientationRight];
    finalImage = rotatedImage;
}

javascript: detect scroll end

This will actually be the correct answer:

function scrolled(event) {
   const container = event.target.body
   const {clientHeight, scrollHeight, scrollY: scrollTop} = container

   if (clientHeight + scrollY >= scrollHeight) {
    scrolledToBottom(event);
   }
}

The reason for using the event is up-to-date data, if you'll use a direct reference to the div you'll get outdated scrollY and will fail to detect the position correctly.

additional way is to wrap it in a setTimeout and wait till the data updates.

Change background colour for Visual Studio

Visual Studio Code Editor In File->Preferences->Color Theme

Return JSON response from Flask view

Pass keyword arguments to flask.jsonify and they will be output as a JSON object.

@app.route('/_get_current_user')
def get_current_user():
    return jsonify(
        username=g.user.username,
        email=g.user.email,
        id=g.user.id
    )
{
    "username": "admin",
    "email": "admin@localhost",
    "id": 42
}

If you already have a dict, you can pass it directly as jsonify(d).

Android Layout Weight

<LinearLayout
    android:id="@+id/linear1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:weightSum="9"
    android:orientation="horizontal" >

    <ImageView
        android:id="@+id/ring_oss"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:src="@drawable/ring_oss" />

    <ImageView
        android:id="@+id/maila_oss"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:src="@drawable/maila_oss" />
<EditText
        android:id="@+id/edittxt"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:src="@drawable/maila_oss" />
</LinearLayout>

Does MySQL foreign_key_checks affect the entire database?

I had the same error when I tried to migrate Drupal database to a new local apache server(I am using XAMPP on Windows machine). Actually I don't know the meaning of this error, but after trying steps below, I imported the database without errors. Hope this could help:

Changing php.ini at C:\xampp\php\php.ini

max_execution_time = 600
max_input_time = 600
memory_limit = 1024M
post_max_size = 1024M

Changing my.ini at C:\xampp\mysql\bin\my.ini

max_allowed_packet = 1024M

Rounding up to next power of 2

import sys


def is_power2(x):
    return x > 0 and ((x & (x - 1)) == 0)


def find_nearest_power2(x):
    if x <= 0:
        raise ValueError("invalid input")
    if is_power2(x):
        return x
    else:
        bits = get_bits(x)
        upper = 1 << (bits)
        lower = 1 << (bits - 1)
        mid = (upper + lower) // 2
        if (x - mid) > 0:
            return upper
        else:
            return lower


def get_bits(x):
    """return number of bits in binary representation"""
    if x < 0:
        raise ValueError("invalid input: input should be positive integer")
    count = 0
    while (x != 0):
        try:
            x = x >> 1
        except TypeError as error:
            print(error, "input should be of type integer")
            sys.exit(1)
        count += 1
    return count

How to change default JRE for all Eclipse workspaces?

try to change the order: right click on you project-> BuildPath->Configure...->Order and Export tab -> move jre7 UP.

Error in launching AVD with AMD processor

For AMD processors:

You don't need Genymotion, just create a new Virtual Device and while selecting the system Image select the ABI as armeabi instead of the default x86 one.

enter image description here

Map implementation with duplicate keys

I had a slightly different variant of this issue: It was required to associate two different values with same key. Just posting it here in case it helps others, I have introduced a HashMap as the value:

/* @param frameTypeHash: Key -> Integer (frameID), Value -> HashMap (innerMap)
   @param innerMap: Key -> String (extIP), Value -> String
   If the key exists, retrieve the stored HashMap innerMap 
   and put the constructed key, value pair
*/
  if (frameTypeHash.containsKey(frameID)){
            //Key exists, add the key/value to innerHashMap
            HashMap innerMap = (HashMap)frameTypeHash.get(frameID);
            innerMap.put(extIP, connName+":"+frameType+":"+interfaceName);

        } else {
            HashMap<String, String> innerMap = new HashMap<String, String>();
            innerMap.put(extIP, connName+":"+frameType+":"+interfaceName);
            // This means the key doesn't exists, adding it for the first time
            frameTypeHash.put(frameID, innerMap );
        }
}

In the above code the key frameID is read from a input file's first string in each line, the value for frameTypeHash is constructed by splitting the remaining line and was stored as String object originally, over a period of time the file started having multiple lines (with different values) associated with same frameID key, so frameTypeHash was overwritten with last line as the value. I replaced the String object with another HashMap object as the value field, this helped in maintaining single key to different value mapping.

C#: Dynamic runtime cast

Slight modification on @JRodd version to support objects coming from Json (JObject)

public static dynamic ToDynamic(this object value)
    {
        IDictionary<string, object> expando = new ExpandoObject();

        //Get the type of object 
        Type t = value.GetType();

        //If is Dynamic Expando object
        if (t.Equals(typeof(ExpandoObject)))
        {
            foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(value.GetType()))
                expando.Add(property.Name, property.GetValue(value));
        }
        //If coming from Json object
        else if (t.Equals(typeof(JObject)))
        {
            foreach (JProperty property in (JToken)value)
                expando.Add(property.Name, property.Value);
        }
        else //Try converting a regular object
        {
            string str = JsonConvert.SerializeObject(value);
            ExpandoObject obj = JsonConvert.DeserializeObject<ExpandoObject>(str);

            return obj;
        }

       

        return expando as ExpandoObject;
    }

SVN Commit specific files

You basically put the files you want to commit on the command line

svn ci file1 file2 dir1/file3

Order columns through Bootstrap4

2018 - Revisiting this question with the latest Bootstrap 4.

The responsive ordering classes are now order-first, order-last and order-0 - order-12

The Bootstrap 4 push pull classes are now push-{viewport}-{units} and pull-{viewport}-{units} and the xs- infix has been removed. To get the desired 1-3-2 layout on mobile/xs would be: Bootstrap 4 push pull demo (This only works pre 4.0 beta)


Bootstrap 4.1+

Since Bootstrap 4 is flexbox, it's easy to change the order of columns. The cols can be ordered from order-1 to order-12, responsively such as order-md-12 order-2 (last on md, 2nd on xs) relative to the parent .row.

<div class="container">
    <div class="row">
        <div class="col-3 col-md-6">
            <div class="card card-body">1</div>
        </div>
        <div class="col-6 col-md-12 order-2 order-md-12">
            <div class="card card-body">3</div>
        </div>
        <div class="col-3 col-md-6 order-3">
            <div class="card card-body">2</div>
        </div>
    </div>
</div>

Demo: Change order using order-* classes

Desktop (larger screens): enter image description here

Mobile (smaller screens): enter image description here

It's also possible to change column order using the flexbox direction utils...

<div class="container">
    <div class="row flex-column-reverse flex-md-row">
        <div class="col-md-8">
            2
        </div>
        <div class="col-md-4">
            1st on mobile
        </div>
    </div>
</div>

Demo: Bootstrap 4.1 Change Order with Flexbox Direction


Older version demos
demo - alpha 6
demo - beta (3)

See more Bootstrap 4.1+ ordering demos


Related:
Column ordering in Bootstrap 4 with push/pull and col-md-12
Bootstrap 4 change order of columns

A-C-B A-B-C

How can I copy the output of a command directly into my clipboard?

In Linux with xclip installed:

xclip -selection clipboard < file

How do you extract a JAR in a UNIX filesystem with a single command and specify its target directory using the JAR command?

I don't think the jar tool supports this natively, but you can just unzip a JAR file with "unzip" and specify the output directory with that with the "-d" option, so something like:

$ unzip -d /home/foo/bar/baz /home/foo/bar/Portal.ear Binaries.war

Subversion stuck due to "previous operation has not finished"?

I had the same issue, what worked for me:

  1. Copy your folders and files to another place, say to a folder (I changed my files recently and the commitment failed and led to the addressed problem)
  2. check out a new working copy
  3. copy your changed files from folder to your working copy and override existing files. Commiting / Updating should work now

How can I return the difference between two lists?

With Stream API you can do something like this:

List<String> aWithoutB = a.stream()
    .filter(element -> !b.contains(element))
    .collect(Collectors.toList());

List<String> bWithoutA = b.stream()
    .filter(element -> !a.contains(element))
    .collect(Collectors.toList());

how to check confirm password field in form without reloading page

WITHOUT clicking the button you will have to listen to the change event of the input fields

var confirmField = document.getElementById("confirm_password");
var passwordField = document.getElementById("password");

function checkPasswordMatch(){
    var status = document.getElementById("password_status");
    var submit = document.getElementById("submit");

    status.innerHTML = "";
    submit.removeAttribute("disabled");

    if(confirmField.value === "")
        return;

    if(passwordField.value === confirmField.value)
        return;

    status.innerHTML = "Passwords don't match";
    submit.setAttribute("disabled", "disabled");
}

passWordField.addEventListener("change", function(event){
    checkPasswordMatch();
});
confirmField.addEventListener("change", function(event){
    checkPasswordMatch();
});

then add the status element to your html:

<p id="password_status"></p>

and set the submit button id to submit

... id="submit" />

hope this helps you

Why is my CSS style not being applied?

I also faced this issue. And this how it got resolved!

My css filename was gt.css. I was working on Visual Studio (eg.2017).

  • I went to solution explorer (press Ctrl+Alt+L) and searched gt.css (enter your css filename). Right click on your css filename and then on Bundler and Minifier (4th option curently) and then Re-Bundle file (or directly press Shift+Alt+F).
  • Save any unsaved file, then empty cache and hard reload your web browser.

You can learn more about Bundler and Minifier here.

LINQ to SQL Left Outer Join

Take care of performance:

I experienced that at least with EF Core the different answers given here might result in different performance. I'm aware that the OP asked about Linq to SQL, but it seems to me that the same questions occur also with EF Core.

In a specific case I had to handle, the (syntactically nicer) suggestion by Marc Gravell resulted in left joins inside a cross apply -- similarly to what Mike U described -- which had the result that the estimated costs for this specific query were two times as high compared to a query with no cross joins. The server execution times differed by a factor of 3. [1]

The solution by Marc Gravell resulted in a query without cross joins.

Context: I essentially needed to perform two left joins on two tables each of which again required a join to another table. Furthermore, there I had to specify other where-conditions on the tables on which I needed to apply the left join. In addition, I had two inner joins on the main table.

Estimated operator costs:

  • with cross apply: 0.2534
  • without cross apply: 0.0991.

Server execution times in ms (queries executed 10 times; measured using SET STATISTICS TIME ON):

  • with cross apply: 5, 6, 6, 6, 6, 6, 6, 6, 6, 6
  • without cross apply: 2, 2, 2, 2, 2, 2, 2, 2, 2, 2

(The very first run was slower for both queries; seems that something is cached.)

Table sizes:

  • main table: 87 rows,
  • first table for left join: 179 rows;
  • second table for left join: 7 rows.

EF Core version: 2.2.1.

SQL Server version: MS SQL Server 2017 - 14... (on Windows 10).

All relevant tables had indexes on the primary keys only.

My conclusion: it's always recommended to look at the generated SQL since it can really differ.


[1] Interestingly enough, when setting the 'Client statistics' in MS SQL Server Management Studio on, I could see an opposite trend; namely that last run of the solution without cross apply took more than 1s. I suppose that something was going wrong here - maybe with my setup.

simple custom event

Events are pretty easy in C#, but the MSDN docs in my opinion make them pretty confusing. Normally, most documentation you see discusses making a class inherit from the EventArgs base class and there's a reason for that. However, it's not the simplest way to make events, and for someone wanting something quick and easy, and in a time crunch, using the Action type is your ticket.

Creating Events & Subscribing To Them

1. Create your event on your class right after your class declaration.

public event Action<string,string,string,string>MyEvent;

2. Create your event handler class method in your class.

private void MyEventHandler(string s1,string s2,string s3,string s4)
{
  Console.WriteLine("{0} {1} {2} {3}",s1,s2,s3,s4);
}

3. Now when your class is invoked, tell it to connect the event to your new event handler. The reason the += operator is used is because you are appending your particular event handler to the event. You can actually do this with multiple separate event handlers, and when an event is raised, each event handler will operate in the sequence in which you added them.

class Example
{
  public Example() // I'm a C# style class constructor
  {
    MyEvent += new Action<string,string,string,string>(MyEventHandler);
  }
}

4. Now, when you're ready, trigger (aka raise) the event somewhere in your class code like so:

MyEvent("wow","this","is","cool");

The end result when you run this is that the console will emit "wow this is cool". And if you changed "cool" with a date or a sequence, and ran this event trigger multiple times, you'd see the result come out in a FIFO sequence like events should normally operate.

In this example, I passed 4 strings. But you could change those to any kind of acceptable type, or used more or less types, or even remove the <...> out and pass nothing to your event handler.

And, again, if you had multiple custom event handlers, and subscribed them all to your event with the += operator, then your event trigger would have called them all in sequence.

Identifying Event Callers

But what if you want to identify the caller to this event in your event handler? This is useful if you want an event handler that reacts with conditions based on who's raised/triggered the event. There are a few ways to do this. Below are examples that are shown in order by how fast they operate:

Option 1. (Fastest) If you already know it, then pass the name as a literal string to the event handler when you trigger it.

Option 2. (Somewhat Fast) Add this into your class and call it from the calling method, and then pass that string to the event handler when you trigger it:

private static string GetCaller([System.Runtime.CompilerServices.CallerMemberName] string s = null) => s;

Option 3. (Least Fast But Still Fast) In your event handler when you trigger it, get the calling method name string with this:

string callingMethod = new System.Diagnostics.StackTrace().GetFrame(1).GetMethod().ReflectedType.Name.Split('<', '>')[1];

Unsubscribing From Events

You may have a scenario where your custom event has multiple event handlers, but you want to remove one special one out of the list of event handlers. To do so, use the -= operator like so:

MyEvent -= MyEventHandler;

A word of minor caution with this, however. If you do this and that event no longer has any event handlers, and you trigger that event again, it will throw an exception. (Exceptions, of course, you can trap with try/catch blocks.)

Clearing All Events

Okay, let's say you're through with events and you don't want to process any more. Just set it to null like so:

MyEvent = null;

The same caution for Unsubscribing events is here, as well. If your custom event handler no longer has any events, and you trigger it again, your program will throw an exception.

Bloomberg BDH function with ISIN

I had the same problem. Here's what I figured out:

=BDP(A1&"@BGN Corp", "Issuer_parent_eqy_ticker")

A1 being the ISINs. This will return the ticker number. Then just use the ticker number to get the price.

Android: Create a toggle button with image and no text

create toggle_selector.xml in res/drawable

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@drawable/toggle_on" android:state_checked="true"/>
  <item android:drawable="@drawable/toggle_off" android:state_checked="false"/>
</selector>

apply the selector to your toggle button

<ToggleButton
            android:id="@+id/chkState"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/toggle_selector"
            android:textOff=""
            android:textOn=""/>

Note: for removing the text i used following in above code

textOff=""
textOn=""

How can I write a regex which matches non greedy?

The ? operand makes match non-greedy. E.g. .* is greedy while .*? isn't. So you can use something like <img.*?> to match the whole tag. Or <img[^>]*>.

But remember that the whole set of HTML can't be actually parsed with regular expressions.

How to convert Set<String> to String[]?

In Java 11 we can use Collection.toArray(generator) method. The following code will create a new array of String:

Set<String> set = Set.of("one", "two", "three");
String[] array = set.toArray(String[]::new)

See: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Collection.html#toArray(java.util.function.IntFunction)

Regular expression for matching latitude/longitude coordinates?

PHP

Here is the PHP's version (input values are: $latitude and $longitude):

$latitude_pattern  = '/\A[+-]?(?:90(?:\.0{1,18})?|\d(?(?<=9)|\d?)\.\d{1,18})\z/x';
$longitude_pattern = '/\A[+-]?(?:180(?:\.0{1,18})?|(?:1[0-7]\d|\d{1,2})\.\d{1,18})\z/x';
if (preg_match($latitude_pattern, $latitude) && preg_match($longitude_pattern, $longitude)) {
  // Valid coordinates.
}

Python conversion from binary string to hexadecimal

int given base 2 and then hex:

>>> int('010110', 2)
22
>>> hex(int('010110', 2))
'0x16'
>>> 

>>> hex(int('0000010010001101', 2))
'0x48d'

The doc of int:

int(x[, base]) -> integer

Convert a string or number to an integer, if possible.  A floating

point argument will be truncated towards zero (this does not include a string representation of a floating point number!) When converting a string, use the optional base. It is an error to supply a base when converting a non-string. If base is zero, the proper base is guessed based on the string content. If the argument is outside the integer range a long object will be returned instead.

The doc of hex:

hex(number) -> string

Return the hexadecimal representation of an integer or long

integer.

How to give a pattern for new line in grep?

Thanks to @jarno I know about the -z option and I found out that when using GNU grep with the -P option, matching against \n is possible. :)

Example:

grep -zoP 'foo\n\K.*'<<<$'foo\nbar'

Prints bar

PHP Warning: mysqli_connect(): (HY000/2002): Connection refused

Sometimes you need to include mysql db port id in the server like so.

$serverName = "127.0.0.1:3307";

How can I download HTML source in C#

You can get it with:

var html = new System.Net.WebClient().DownloadString(siteUrl)

Pull new updates from original GitHub repository into forked GitHub repository

To automatically sync your forked repository with the parent repository, you could use the Pull App on GitHub.

Refer to the Readme for more details.

For advanced setup where you want to preserve your changes done to the forked repository, refer to my answer on a similar question here.

Regex for parsing directory and filename

Most languages have path parsing functions that will give you this already. If you have the ability, I'd recommend using what comes to you for free out-of-the-box.

Assuming / is the path delimiter...

^(.*/)([^/]*)$

The first group will be whatever the directory/path info is, the second will be the filename. For example:

  • /foo/bar/baz.log: "/foo/bar/" is the path, "baz.log" is the file
  • foo/bar.log: "foo/" is the path, "bar.log" is the file
  • /foo/bar: "/foo/" is the path, "bar" is the file
  • /foo/bar/: "/foo/bar/" is the path and there is no file.

Entity Framework Migrations renaming tables and columns

In ef core, you can change the migration that was created after add migration. And then do update-database. A sample has given below:

protected override void Up(MigrationBuilder migrationBuilder)
{
    migrationBuilder.RenameColumn(name: "Type", table: "Users", newName: "Discriminator", schema: "dbo");
}

protected override void Down(MigrationBuilder migrationBuilder)
{            
    migrationBuilder.RenameColumn(name: "Discriminator", table: "Users", newName: "Type", schema: "dbo");
}

How to set IE11 Document mode to edge as default?

try to add this section in your web.config file on web server, sometimes it happens with php pages:

<httpProtocol>
    <customHeaders>
        <clear />
        <add name="X-UA-Compatible" value="IE=edge" />
    </customHeaders>
</httpProtocol>

Why does Java's hashCode() in String use 31 as a multiplier?

You can read Bloch's original reasoning under "Comments" in http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4045622. He investigated the performance of different hash functions in regards to the resulting "average chain size" in a hash table. P(31) was one of the common functions during that time which he found in K&R's book (but even Kernighan and Ritchie couldn't remember where it came from). In the end he basically had to choose one and so he took P(31) since it seemed to perform well enough. Even though P(33) was not really worse and multiplication by 33 is equally fast to calculate (just a shift by 5 and an addition), he opted for 31 since 33 is not a prime:

Of the remaining four, I'd probably select P(31), as it's the cheapest to calculate on a RISC machine (because 31 is the difference of two powers of two). P(33) is similarly cheap to calculate, but it's performance is marginally worse, and 33 is composite, which makes me a bit nervous.

So the reasoning was not as rational as many of the answers here seem to imply. But we're all good in coming up with rational reasons after gut decisions (and even Bloch might be prone to that).

JavaScript: Difference between .forEach() and .map()

forEach: If you want to perform an action on the elements of an Array and it is same as you use for loop. The result of this method does not give us an output buy just loop through the elements.

map: If you want to perform an action on the elements of an array and also you want to store the output of your action into an Array. This is similar to for loop within a function that returns the result after each iteration.

Hope this helps.

Convert xlsx file to csv using batch

To follow up on the answer by user183038, here is a shell script to batch rename all xlsx files to csv while preserving the file names. The xlsx2csv tool needs to be installed prior to running.

for i in *.xlsx;
 do
  filename=$(basename "$i" .xlsx);
  outext=".csv" 
  xlsx2csv $i $filename$outext
done

Searching for Text within Oracle Stored Procedures

I allways use UPPER(text) like UPPER('%blah%')

Finding the Eclipse Version Number

(Update September 2012):

MRT points out in the comments that "Eclipse Version" question references a .eclipseproduct in the main folder, and it contains:

name=Eclipse Platform
id=org.eclipse.platform
version=3.x.0

So that seems more straightforward than my original answer below.

Also, Neeme Praks mentions below that there is a eclipse/configuration/config.ini which includes a line like:

eclipse.buildId=4.4.1.M20140925-0400

Again easier to find, as those are Java properties set and found with System.getProperty("eclipse.buildId").


Original answer (April 2009)

For Eclipse Helios 3.6, you can deduce the Eclipse Platform version directly from the About screen:
It is a combination of the Eclipse global version and the build Id:

alt text

Here is an example for Eclipse 3.6M6:
The version would be: 3.6.0.v201003121448, after the version 3.6.0 and the build Id I20100312-1448 (an Integration build from March 12th, 2010 at 14h48

To see it more easily, click on "Plugin Details" and sort by Version.


Note: Eclipse3.6 has a brand new cool logo:

alt text

And you can see the build Id now being displayed during the loading step of the different plugin.

Round to 2 decimal places

Just use Math.round()

double mkm = ((((amountdrug/fluidvol)*1000f)/60f)*infrate)/ptwt;

mkm= (double)(Math.round(mkm*100))/100;

FileNotFoundError: [Errno 2] No such file or directory

with open(fpath, 'rb') as myfile:
    fstr = myfile.read()

I encounter this error because the file is empty. This answer may not a correct answer for this question but should give developers a hint like me.

jQuery 'input' event

Using jQuery, the following are identical in effect:

$('a').click(function(){ doSomething(); });
$('a').on('click', function(){ doSomething(); });

With the input event, however, only the second pattern seems to work in the browsers I've tested.

Thus, you'd expect this to work, but it DOES NOT (at least currently):

$(':text').input(function(){ doSomething(); });

Again, if you wanted to leverage event delegation (e.g. to set up the event on the #container before your input.text is added to the DOM), this should come to mind:

$('#container').on('input', ':text', function(){ doSomething(); });

Sadly, again, it DOES NOT work currently!

Only this pattern works:

$(':text').on('input', function(){ doSomething(); });

EDITED WITH MORE CURRENT INFORMATION

I can certainly confirm that this pattern:

$('#container').on('input', ':text', function(){ doSomething(); });

NOW WORKS also, in all 'standard' browsers.

Including a css file in a blade template?

@include directive allows you to include a Blade view from within another view, like this :

@include('another.view')

Include CSS or JS from master layout

asset()

The asset function generates a URL for an asset using the current scheme of the request (HTTP or HTTPS):

<link href="{{ asset('css/styles.css') }}" rel="stylesheet">
<script type="text/javascript" src="{{ asset('js/scripts.js') }}"></script>

mix()

If you are using versioned Mix file, you can also use mix() function. It will returns the path to a versioned Mix file:

<link href="{{ mix('css/styles.css') }}" rel="stylesheet">
<script type="text/javascript" src="{{ mix('js/scripts.js') }}"></script>

Incude CSS or JS from sub-view, use @push().

layout.blade.php

<html>
    <head>
        <!-- push target to head -->
        @stack('styles')
        @stack('scripts')
    </head>
    <body>

        <!-- or push target to footer -->
        @stack('scripts')
    </body>
</html

view.blade.php

@push('styles')
    <link href="{{ asset('css/styles.css') }}" rel="stylesheet">
@endpush

@push('scripts')
    <script type="text/javascript" src="{{ asset('js/scripts.js') }}"></script>
@endpush

Why can I not switch branches?

Since the file is modified by both, Either you need to add it by

git add Whereami.xcodeproj/project.xcworkspace/xcuserdatauser.xcuserdatad/UserInterfaceState.xcuserstate

Or if you would like to ignore yoyr changes, then do

git reset HEAD Whereami.xcodeproj/project.xcworkspace/xcuserdatauser.xcuserdatad/UserInterfaceState.xcuserstate

After that just switch your branch.This should do the trick.

window.onload vs <body onload=""/>

window.onload = myOnloadFunc and <body onload="myOnloadFunc();"> are different ways of using the same event. Using window.onload is less obtrusive though - it takes your JavaScript out of the HTML.

All of the common JavaScript libraries, Prototype, ExtJS, Dojo, JQuery, YUI, etc. provide nice wrappers around events that occur as the document is loaded. You can listen for the window onLoad event, and react to that, but onLoad is not fired until all resources have been downloaded, so your event handler won't be executed until that last huge image has been fetched. In some cases that's exactly what you want, in others you might find that listening for when the DOM is ready is more appropriate - this event is similar to onLoad but fires without waiting for images, etc. to download.

Plot Normal distribution with Matplotlib

Note: This solution is using pylab, not matplotlib.pyplot

You may try using hist to put your data info along with the fitted curve as below:

import numpy as np
import scipy.stats as stats
import pylab as pl

h = sorted([186, 176, 158, 180, 186, 168, 168, 164, 178, 170, 189, 195, 172,
     187, 180, 186, 185, 168, 179, 178, 183, 179, 170, 175, 186, 159,
     161, 178, 175, 185, 175, 162, 173, 172, 177, 175, 172, 177, 180])  #sorted

fit = stats.norm.pdf(h, np.mean(h), np.std(h))  #this is a fitting indeed

pl.plot(h,fit,'-o')

pl.hist(h,normed=True)      #use this to draw histogram of your data

pl.show()                   #use may also need add this 

enter image description here

Undefined reference to sqrt (or other mathematical functions)

Just adding the #include <math.h> in c source file and -lm in Makefile at the end will work for me.

    gcc -pthread -o p3 p3.c -lm

How to check if the request is an AJAX request with PHP

From PHP 7 with null coalescing operator it will be shorter:

$is_ajax = 'xmlhttprequest' == strtolower( $_SERVER['HTTP_X_REQUESTED_WITH'] ?? '' );

List names of all tables in a SQL Server 2012 schema

SELECT t1.name AS [Schema], t2.name AS [Table]
FROM sys.schemas t1
INNER JOIN sys.tables t2
ON t2.schema_id = t1.schema_id
ORDER BY t1.name,t2.name

How to get all possible combinations of a list’s elements?

Here is one using recursion:

>>> import copy
>>> def combinations(target,data):
...     for i in range(len(data)):
...         new_target = copy.copy(target)
...         new_data = copy.copy(data)
...         new_target.append(data[i])
...         new_data = data[i+1:]
...         print new_target
...         combinations(new_target,
...                      new_data)
...                      
... 
>>> target = []
>>> data = ['a','b','c','d']
>>> 
>>> combinations(target,data)
['a']
['a', 'b']
['a', 'b', 'c']
['a', 'b', 'c', 'd']
['a', 'b', 'd']
['a', 'c']
['a', 'c', 'd']
['a', 'd']
['b']
['b', 'c']
['b', 'c', 'd']
['b', 'd']
['c']
['c', 'd']
['d']

Best way to iterate through a Perl array

If you only care about the elements of @Array, use:

for my $el (@Array) {
# ...
}

or

If the indices matter, use:

for my $i (0 .. $#Array) {
# ...
}

Or, as of perl 5.12.1, you can use:

while (my ($i, $el) = each @Array) {
# ...
}

If you need both the element and its index in the body of the loop, I would expect using each to be the fastest, but then you'll be giving up compatibility with pre-5.12.1 perls.

Some other pattern than these might be appropriate under certain circumstances.

How to remove part of a string before a ":" in javascript?

There is no need for jQuery here, regular JavaScript will do:

var str = "Abc: Lorem ipsum sit amet";
str = str.substring(str.indexOf(":") + 1);

Or, the .split() and .pop() version:

var str = "Abc: Lorem ipsum sit amet";
str = str.split(":").pop();

Or, the regex version (several variants of this):

var str = "Abc: Lorem ipsum sit amet";
str = /:(.+)/.exec(str)[1];

How do I use the CONCAT function in SQL Server 2008 R2?

CONCAT, as stated, is not supported prior to SQL Server 2012. However you can concatenate simply using the + operator as suggested. But beware, this operator will throw an error if the first operand is a number since it thinks will be adding and not concatenating. To resolve this issue just add '' in front. For example

someNumber + 'someString' + .... + lastVariableToConcatenate

will raise an error BUT '' + someNumber + 'someString' + ...... will work just fine.

Also, if there are two numbers to be concatenated make sure you add a '' between them, like so

.... + someNumber + '' + someOtherNumber + .....

Axios Delete request with body and headers?

axios.delete is passed a url and an optional configuration.

axios.delete(url[, config])

The fields available to the configuration can include the headers.

This makes it so that the API call can be written as:

const headers = {
  'Authorization': 'Bearer paperboy'
}
const data = {
  foo: 'bar'
}

axios.delete('https://foo.svc/resource', {headers, data})

Twitter Bootstrap date picker

You used data-datepicker="datepicker" It must be date-provide="datepicker"

Also, you included 2 bootstrap stylesheets bootstrap.css and bootstrap.min.css

I also prefer to use bootstrap-datepicker3.min.css than datepicker.less

Full Html:

<html>
    <head>
    <title>DatePicker Demo</title>
    <link href="css/bootstrap.min.css" rel="stylesheet" type="text/css" />
    <link rel="stylesheet" href="css/bootstrap-datepicker3.min.css">
    <script src="js/jquery-1.7.1.js"></script>
    <script src="js/bootstrap-datepicker.js"></script>
    </head>
    <body>
        <form>
            <div class="input">
                <input data-provide="datepicker" class="small" type="text" value="01/05/2011">
            </div>
        </form>
    </body>
</html>

How can I convert spaces to tabs in Vim or Linux?

1 - If you have spaces and want tabs.

First, you need to decide how many spaces will have a single tab. That said, suppose you have lines with leading 4 spaces, or 8... Than you realize you probably want a tab to be 4 spaces. Now with that info, you do:

:set ts=4
:set noet
:%retab!

There is a problem here! This sequence of commands will look for all your text, not only spaces in the begin of the line. That mean a string like: "Hey,?this????is?4?spaces" will become "Hey,?this?is?4?spaces", but its not! its a tab!.

To settle this little problem I recomend a search, instead of retab.

:%s/^\(^I*\)????/\1^I/g

This search will look in the whole file for any lines starting with whatever number of tabs, followed by 4 spaces, and substitute it for whatever number of tabs it found plus one.

This, unfortunately, will not run at once!

At first, the file will have lines starting with spaces. The search will then convert only the first 4 spaces to a tab, and let the following...

You need to repeat the command. How many times? Until you get a pattern not found. I cannot think of a way to automatize the process yet. But if you do:

`10@:`

You are probably done. This command repeats the last search/replace for 10 times. Its not likely your program will have so many indents. If it has, just repeat again @@.

Now, just to complete the answer. I know you asked for the opposite, but you never know when you need to undo things.

2 - You have tabs and want spaces.

First, decide how many spaces you want your tabs to be converted to. Lets say you want each tab to be 2 spaces. You then do:

:set ts=2
:set et
:%retab!

This would have the same problem with strings. But as its better programming style to not use hard tabs inside strings, you actually are doing a good thing here. If you really need a tab inside a string, use \t.

Initialize 2D array

Easy to read/type.

  table = new char[][] {
      "0123456789".toCharArray()
    , "abcdefghij".toCharArray()
  };

Why does cURL return error "(23) Failed writing body"?

You can do this instead of using -o option:

curl [url] > [file]

PHP mail not working for some reason

This might be the issue of your SMTP config in your php.ini file.

Since you new to PHP, You can find php.ini file in your root directory of PHP installation folder and check for SMTP = and smtp_port= and change the value to

SMTP = your mail server e.g) mail.yourdomain.com
smtp_port = 25(check your admin for original port)

In case your server require authentication for sending mail, use PEAR mail function.

Updating version numbers of modules in a multi-module Maven project

The given answer assumes that the project in question use project inheritance in addition to module aggregation. In fact those are distinct concepts:

https://maven.apache.org/guides/introduction/introduction-to-the-pom.html#Project_Inheritance_vs_Project_Aggregation

Some projects may be an aggregation of modules, yet not have a parent-child relationship between aggregator POM and the aggregated modules. (There may be no parent-child relationship at all, or the child modules may use a separate POM altogether as the "parent".) In these situations the given answer will not work.

After much reading and experimentation, it turns out there is a way to use the Versions Maven Plugin to update not only the aggregator POM but also all aggregated modules as well; it is the processAllModules option. The following command must be done in the directory of the aggregator project:

mvn versions:set -DnewVersion=2.50.1-SNAPSHOT -DprocessAllModules

The Versions Maven Plugin will not only update the versions of all contained modules, it will also update inter-module dependencies!!!! This is a huge win and will save a lot of time and prevent all sorts of problems.

Of course don't forget to commit the changes in all modules, which you can also do with the same switch:

mvn versions:commit -DprocessAllModules

You may decide to dispense with the backup POMS altogether and do everything in one command:

mvn versions:set -DnewVersion=2.50.1-SNAPSHOT -DprocessAllModules -DgenerateBackupPoms=false

Convert an enum to List<string>

I want to add another solution: In my case, I need to use a Enum group in a drop down button list items. So they might have space, i.e. more user friendly descriptions needed:

  public enum CancelReasonsEnum
{
    [Description("In rush")]
    InRush,
    [Description("Need more coffee")]
    NeedMoreCoffee,
    [Description("Call me back in 5 minutes!")]
    In5Minutes
}

In a helper class (HelperMethods) I created the following method:

 public static List<string> GetListOfDescription<T>() where T : struct
    {
        Type t = typeof(T);
        return !t.IsEnum ? null : Enum.GetValues(t).Cast<Enum>().Select(x => x.GetDescription()).ToList();
    }

When you call this helper you will get the list of item descriptions.

 List<string> items = HelperMethods.GetListOfDescription<CancelReasonEnum>();

ADDITION: In any case, if you want to implement this method you need :GetDescription extension for enum. This is what I use.

 public static string GetDescription(this Enum value)
    {
        Type type = value.GetType();
        string name = Enum.GetName(type, value);
        if (name != null)
        {
            FieldInfo field = type.GetField(name);
            if (field != null)
            {
                DescriptionAttribute attr =Attribute.GetCustomAttribute(field,typeof(DescriptionAttribute)) as DescriptionAttribute;
                if (attr != null)
                {
                    return attr.Description;
                }
            }
        }
        return null;
        /* how to use
            MyEnum x = MyEnum.NeedMoreCoffee;
            string description = x.GetDescription();
        */

    }