Programs & Examples On #Andand

Bootstrap 3 .col-xs-offset-* doesn't work?

Alternatively, you can add an empty div for the xs-offset (would save you having to manage the content in more than one place)

<div class="col-xs-1 visible-xs"></div><div class="col-xs-2">col</div>

The bootstrap devs seem to be refusing to add those xs- ofsets and push/pull classes, see here:

SoapUI "failed to load url" error when loading WSDL

i got same error but actually due to this link(WSDL URL) not accessible from Machine. so please check first on browser(client) response after hitting URL ie if giving response as wsdl file or not then check it SOAP UI.

For eg: url?wsdl

How to drop a table if it exists?

    DROP TABLE Scores

Error installing mysql2: Failed to build gem native extension

For MacOS Mojave:

gem install mysql2 -v '0.5.2' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include

Send POST data via raw json with postman

Install Postman native app, Chrome extension has been deprecated. (Mine was opening in own window but still ran as Chrome app)

Bootstrap button drop-down inside responsive table not visible because of scroll

Inside bootstrap.css search the next code:

.fixed-table-body {
  overflow-x: auto;
  overflow-y: auto;
  height: 100%;

...and update with this:

.fixed-table-body {
  overflow-x: visible;
  overflow-y: visible;
  height: 100%;

Is it possible to center text in select box?

While you cannot center the option text within a select, you can lay an absolutely positioned div over the top of the select to the same effect:

  position: absolute;
  top: 10px;
  left: 10px;
  width: 818px;
  height: 37px;
  text-align: center;
  font: bold 24pt calibri;
  background-color: white;
  z-index: 100;

  position: absolute;
  top: 10px;
  left: 10px;
  width: 840px;
  height: 40px;
  font: bold 24pt calibri;

$('#selectToCenter').on('change', function () {

<select id="selectToCenter"></select>
<div id="centered"></div>

Make sure the both the div and select have fixed positions in the document.

How to change date format (MM/DD/YY) to (YYYY-MM-DD) in date picker

You need something like this during the initialization of your datepicker:

$("#your_elements_id").datepicker({ dateFormat: 'yyyy-mm-dd' });

How to export JSON from MongoDB using Robomongo

I had this same issue, and running script in robomongo (Robo 3T 1.1.1) also doesn't allow to copy values and there was no export option either. The best way I could achieve this is to use mongoexport, if mongodb is installed on your local, you can use mongoexport to connect to database on any server and extract data

To connect to Data on remote server, and csv output file, run the following mongoexport in your command line

mongoexport --host HOSTNAME --port PORT --username USERNAME --password "PASSWORD" --collection COLLECTION_NAME --db DATABASE_NAME --out OUTPUTFILE.csv --type=csv --fieldFile fields.txt

fieldFile: helps to extract the desired columns, ex: contents of fields.txt can be just:


to only extract values of the column 'userId'

Data on remote server, json output file:

mongoexport --host HOST_NAME --port PORT --username USERNAME --password "PASSWORD" --collection COLECTION_NAME --db DATABASE_NAME --out OUTPUT.json

this extracts all fields into the json file

data on localhost (mongodb should be running on localhost)

mongoexport --db DATABASE_NAME --collection COLLECTION --out OUTPUT.json


How to debug an apache virtual host configuration?

I found my own mistake, I did not add log file name: ErrorLog /var/log/apache2
And this path: Directory "/usr/share/doc/" Did not contain website sources.

After I changed these two, all worked. Interestingly, apache did not issue any errors, just did not open my website silently on my Mac OS Sierra.

How to unlock android phone through ADB

if the device is locked with black screen run the following:

  1. adb shell input keyevent 26 - this will turn screen on
  2. adb shell input keyevent 82 - this will unlock and ask for pin
  3. adb shell input text xxxx && adb shell input keyevent 66 - this will input your pin and press enter, unlocking device to home screen


The error means that your are trying to look up JNDI name, that is not attached to any EJB component - the component with that name does not exist.

As far as dir structure is concerned: you have to create a JAR file with EJB components. As I understand you want to play with EJB 2.X components (at least the linked example suggests that) so the structure of the JAR file should be:

/com/mypackage/MyEJB.class /com/mypackage/MyEJBInterface.class /com/mypackage/etc... etc... java classes /META-INF/ejb-jar.xml /META-INF/jboss.xml

The JAR file is more or less ZIP file with file extension changed from ZIP to JAR.

BTW. If you use JBoss 5, you can work with EJB 3.0, which are much more easier to configure. The simplest component is

public class MyEJB implements MyEJBInterface{
   public void bussinesMethod(){


No ejb-jar.xml, jboss.xml is needed, just EJB JAR with MyEJB and MyEJBInterface compiled classes.

Now in your client code you need to lookup "MyComponentName".

How to use EOF to run through a text file in C?

One possible C loop would be:

#include <stdio.h>
int main()
    int c;
    while ((c = getchar()) != EOF)
        ** Do something with c, such as check against '\n'
        ** and increment a line counter.

For now, I would ignore feof and similar functions. Exprience shows that it is far too easy to call it at the wrong time and process something twice in the belief that eof hasn't yet been reached.

Pitfall to avoid: using char for the type of c. getchar returns the next character cast to an unsigned char and then to an int. This means that on most [sane] platforms the value of EOF and valid "char" values in c don't overlap so you won't ever accidentally detect EOF for a 'normal' char.

How to set upload_max_filesize in .htaccess?

Both commands are correct

php_value post_max_size 30M 
php_value upload_max_filesize 30M 

BUT to use the .htaccess you have to enable rewrite_module in Apache config file. In httpd.conf find this line:

# LoadModule rewrite_module modules/

and remove the #.

Running multiple async tasks and waiting for them all to complete

There should be a more succinct solution than the accepted answer. It shouldn't take three steps to run multiple tasks simultaneously and get their results.

  1. Create tasks
  2. await Task.WhenAll(tasks)
  3. Get task results (e.g., task1.Result)

Here's a method that cuts this down to two steps:

    public async Task<Tuple<T1, T2>> WhenAllGeneric<T1, T2>(Task<T1> task1, Task<T2> task2)
        await Task.WhenAll(task1, task2);
        return Tuple.Create(task1.Result, task2.Result);

You can use it like this:

var taskResults = await Task.WhenAll(DoWorkAsync(), DoMoreWorkAsync());
var DoWorkResult = taskResults.Result.Item1;
var DoMoreWorkResult = taskResults.Result.Item2;

This removes the need for the temporary task variables. The problem with using this is that while it works for two tasks, you'd need to update it for three tasks, or any other number of tasks. Also it doesn't work well if one of the tasks doesn't return anything. Really, the .Net library should provide something that can do this

Django -- Template tag in {% if %} block

You try this.

I have already tried it in my django template.

It will work fine. Just remove the curly braces pair {{ and }} from {{source}}.

I have also added <table> tag and that's it.

After modification your code will look something like below.

{% for source in sources %}
          <td>{{ source }}</td>
              {% if title == source %}
                Just now! 
              {% endif %}
{% endfor %}

My dictionary looks like below,

{'title':"Rishikesh", 'sources':["Hemkesh", "Malinikesh", "Rishikesh", "Sandeep", "Darshan", "Veeru", "Shwetabh"]}

and OUTPUT looked like below once my template got rendered.

Rishikesh   Just now!

How does += (plus equal) work?

x+=y is shorthand in many languages for set x to x + y. The sum will be, as hinted by its name, the sum of the numbers in data.

How to manipulate arrays. Find the average. Beginner Java

If we want to add numbers of an Array and find the average of them follow this easy way! .....

public class Array {

    public static void main(String[] args) {

        int[]array = {1,3,5,7,9,6,3};
        int i=0;
        int sum=0;
        double average=0;
        for( i=0;i<array.length;i++){
        System.out.println("sum is:"+sum);
        System.out.println("average is: "+(double)sum/vargu.length);



Detect rotation of Android phone in the browser with JavaScript

A little contribution to the two-bit-fool's answer:

As described on the table on droid phones "orientationchange" event gets fired earlier than "resize" event thus blocking the next resize call (because of the if statement). Width property is still not set.

A workaround though maybe not a perfect one could be to not fire the "orientationchange" event. That can be archived by wrapping "orientationchange" event binding in "if" statement:

if (!navigator.userAgent.match(/android/i))
    window.addEventListener("orientationchange", checkOrientation, false);

Hope it helps

(tests were done on Nexus S)

How can I invert color using CSS?

Add the same color of the background to the paragraph and then invert with CSS:

div {_x000D_
    background-color: #f00;_x000D_
p { _x000D_
    color: #f00;_x000D_
    -webkit-filter: invert(100%);_x000D_
    filter: invert(100%);_x000D_
    <p>inverted color</p>_x000D_

Is there a free GUI management tool for Oracle Database Express?

you can always use the web based management tool that comes with oracle express db.. have tried using it? you can access it through http://host:port/apex if i remember correctly...

Alternative solutions are Oracle SQL Developer, TOAD etc...

Converting strings to floats in a DataFrame

df['MyColumnName'] = df['MyColumnName'].astype('float64') 

How does #include <bits/stdc++.h> work in C++?

That header file is not part of the C++ standard, is therefore non-portable, and should be avoided.

Moreover, even if there were some catch-all header in the standard, you would want to avoid it in lieu of specific headers, since the compiler has to actually read in and parse every included header (including recursively included headers) every single time that translation unit is compiled.

Format of the initialization string does not conform to specification starting at index 0

As I Know, whenever you have more than 1 connection string in your solution(your current project, startup project,...), you may confront with this error

this link may help you click

Docker: Multiple Dockerfiles in project

When working on a project that requires the use of multiple dockerfiles, simply create each dockerfile in a separate directory. For instance,

app/ db/

Each of the above directories will contain their dockerfile. When an application is being built, docker will search all directories and build all dockerfiles.

What ports need to be open for TortoiseSVN to authenticate (clear text) and commit?

What's the first part of your Subversion repository URL?

  • If your URL looks like: http://subversion/repos/, then you're probably going over Port 80.
  • If your URL looks like: https://subversion/repos/, then you're probably going over Port 443.
  • If your URL looks like: svn://subversion/, then you're probably going over Port 3690.
  • If your URL looks like: svn+ssh://subversion/repos/, then you're probably going over Port 22.
  • If your URL contains a port number like: http://subversion/repos:8080, then you're using that port.

I can't guarantee the first four since it's possible to reconfigure everything to use different ports, of if you go through a proxy of some sort.

If you're using a VPN, you may have to configure your VPN client to reroute these to their correct ports. A lot of places don't configure their correctly VPNs to do this type of proxying. It's either because they have some sort of anal-retentive IT person who's being overly security conscious, or because they simply don't know any better. Even worse, they'll give you a client where this stuff can't be reconfigured.

The only way around that is to log into a local machine over the VPN, and then do everything from that system.

c# - How to get sum of the values from List?

How about this?

List<string> monValues = Application["mondayValues"] as List<string>;
int sum = monValues.ConvertAll(Convert.ToInt32).Sum();

Getting an object array from an Angular service

Take a look at your code :

 getUsers(): Observable<User[]> {
        return Observable.create(observer => {
            this.http.get('').map(response => response.json();

and code from (BTW. really good tutorial, you should check it out)

 getHeroes(): Promise<Hero[]> {
    return this.http.get(this.heroesUrl)
               .then(response => response.json().data as Hero[])

The HttpService inside Angular2 already returns an observable, sou don't need to wrap another Observable around like you did here:

   return Observable.create(observer => {
        this.http.get('').map(response => response.json()

Try to follow the guide in link that I provided. You should be just fine when you study it carefully.


First of all WHERE you log the this.users variable? JavaScript isn't working that way. Your variable is undefined and it's fine, becuase of the code execution order!

Try to do it like this:

  getUsers(): void {
            .then(users => {
               this.users = users
               console.log('this.users=' + this.users);


See where the console.log(...) is!

Try to resign from toPromise() it's seems to be just for ppl with no RxJs background.

Catch another link: Build your service once again with RxJs observables.

Get column index from label in a data frame

you can get the index via grep and colnames:

grep("B", colnames(df))
[1] 2

or use

grep("^B$", colnames(df))
[1] 2

to only get the columns called "B" without those who contain a B e.g. "ABC".

Turn off auto formatting in Visual Studio

You can tweak the settings of the code formatting. I always turn off all extra line breaks, and then it works fine for how I format the code.

If you tweak the settings as close as you can to your preference, that should leave you minimal work whenever you use refactoring.

Xcode 6 Storyboard the wrong size?

On your storyboard page, go to File Inspector and uncheck 'Use Size Classes'. This should shrink your view controller to regular IPhone size you were familiar with. Note that using 'size classes' will let you design your project across many devices. Once you uncheck this the Xcode will give you a warning dialogue as follows. This should be self-explainatory.

"Disabling size classes will limit this document to storing data for a single device family. The data for the size class best representing the targeted device will be retained, and all other data will be removed. In addition, segues will be converted to their non-adaptive equivalents."

Min and max value of input in angular4 application

[I assume the reader has basic knowledge of Angular2+ and Forms]

It is easy to show a numerical input and put the limits, but you have to also take care of things may happen out of your predictions.

  1. Implement the tag in your 'html':
<input type="number" [min]="0.00" [max]="100.00" [step]="0.01" formControlName="rateFC">
  1. But as Adrien said, still user can enter manually a wrong number. You can validate input by Validators easily. In your '.ts':
import { FormGroup, FormControl, Validators } from '@angular/forms';

//many other things...

this.myFG = new FormGroup({
   //other form controls...,
   rateFC  : new FormControl(0, [Validators.min(0), Validators.max(100)])
  1. Up to now everything is ok, but it is better to let the user know the input is wrong, then draw a red line around the invalid input element by adding to your style:{
    border:2px solid red;
  1. And to make it perfect, prevent the user to submit the wrong data.
<button type="submit" [disabled]="!myFG.valid">Submit</button>

Fatal error: Call to undefined function mysql_connect() in C:\Apache\htdocs\test.php on line 2

I had the similar issue. I solved it the following way after a number of attempts to follow the pieces of advice in the forums. I am reposting the solution because it could be helpful for others.

I am running Windows 7 (Apache 2.2 & PHP 5.2.17 & MySQL 5.0.51a), the syntax in the file "httpd.conf" (C:\Program Files (x86)\Apache Software Foundation\Apache2.2\conf\httpd.conf) was sensitive to slashes. You can check if "php.ini" is read from the right directory. Just type in your browser "localhost/index.php". The code of index.php is the following:

<?php echo phpinfo(); ?>

There is the row (not far from the top) called "Loaded Configuration File". So, if there is nothing added, then the problem could be that your "php.ini" is not read, even you uncommented (extension=php_mysql.dll and extension=php_mysqli.dll). So, in order to make it work I did the following step. I needed to change from

PHPIniDir 'c:\PHP\'


PHPIniDir 'c:\PHP'

Pay the attention that the last slash disturbed everything!

Now the row "Loaded Configuration File" gets "C:\PHP\php.ini" after refreshing "localhost/index.php" (before I restarted Apache2.2) as well as mysql block is there. MySQL and PHP are working together!

Git Pull is Not Possible, Unmerged Files

Assuming you want to throw away any changes you have, first check the output of git status. For any file that says "unmerged" next to it, run git add <unmerged file>. Then follow up with git reset --hard. That will git rid of any local changes except for untracked files.

Get an OutputStream into a String

Here's what I ended up doing:

Obj.writeToStream(toWrite, os);
try {
    String out = new String(os.toByteArray(), "UTF-8");
} catch (UnsupportedEncondingException e) {
    fail("Caught exception: " + e.getMessage());

Where os is a ByteArrayOutputStream.

Execute command on all files in a directory

I needed to copy all .md files from one directory into another, so here is what I did.

for i in **/*.md;do mkdir -p ../docs/"$i" && rm -r ../docs/"$i" && cp "$i" "../docs/$i" && echo "$i -> ../docs/$i"; done

Which is pretty hard to read, so lets break it down.

first cd into the directory with your files,

for i in **/*.md; for each file in your pattern

mkdir -p ../docs/"$i"make that directory in a docs folder outside of folder containing your files. Which creates an extra folder with the same name as that file.

rm -r ../docs/"$i" remove the extra folder that is created as a result of mkdir -p

cp "$i" "../docs/$i" Copy the actual file

echo "$i -> ../docs/$i" Echo what you did

; done Live happily ever after

Example using Hyperlink in WPF

I used the answer in this question and I got an issue with it.

It return exception: {"The system cannot find the file specified."}

After a bit of investigation. It turns out that if your WPF application is CORE, you need to change UseShellExecute to true.

This is mentioned in Microsoft docs:

true if the shell should be used when starting the process; false if the process should be created directly from the executable file. The default is true on .NET Framework apps and false on .NET Core apps.

So to make this work you need to added UseShellExecute and set it to true:

Process.Start(new ProcessStartInfo(e.Uri.AbsoluteUri){ UseShellExecute = true });

Using custom std::set comparator

You can use a function comparator without wrapping it like so:

bool comparator(const MyType &lhs, const MyType &rhs)
    return [...];

std::set<MyType, bool(*)(const MyType&, const MyType&)> mySet(&comparator);

which is irritating to type out every time you need a set of that type, and can cause issues if you don't create all sets with the same comparator.

Understanding the ngRepeat 'track by' expression

a short summary:

track by is used in order to link your data with the DOM generation (and mainly re-generation) made by ng-repeat.

when you add track by you basically tell angular to generate a single DOM element per data object in the given collection

this could be useful when paging and filtering, or any case where objects are added or removed from ng-repeat list.

usually, without track by angular will link the DOM objects with the collection by injecting an expando property - $$hashKey - into your JavaScript objects, and will regenerate it (and re-associate a DOM object) with every change.

full explanation:

a more practical guide:

(track by is available in angular > 1.2 )

How to create a video from images with FFmpeg?

To create frames from video:

ffmpeg\ffmpeg -i %video% test\thumb%04d.jpg -hide_banner

Optional: remove frames you don't want in output video
(more accurate than trimming video with -ss & -t)

Then create video from image/frames eg.:

ffmpeg\ffmpeg -framerate 30 -start_number 56 -i test\thumb%04d.jpg -vf format=yuv420p test/output.mp4

Check if a string contains an element from a list (of strings)

when you construct yours strings it should be like this

bool inact = new string[] { "SUSPENDARE", "DIZOLVARE" }.Any(s=>stare.Contains(s));

How to remove application from app listings on Android Developer Console

Note: Adding a new answer as the publish/unpublish option is moved to different location.

As mentioned in other answers you cannot delete the app. With updated Google Play Console (Beta), the Unpublish option is moved to different location:

Setup -> Advanced Settings -> App Availability

Enable Published / Unpublished accordingly!

enter image description here

json_encode is returning NULL?

I had the same problem and the solution was to use my own function instead of json_encode()

echo '["' . implode('","', $row) . '"]';

Declaration of Methods should be Compatible with Parent Methods in PHP

I faced this problem while trying to extend an existing class from GitHub. I'm gonna try to explain myself, first writing the class as I though it should be, and then the class as it is now.

What I though

namespace mycompany\CutreApi;

use mycompany\CutreApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
   public function whatever(): ClassOfVendor
        return new ClassOfVendor();

What I've finally done

namespace mycompany\CutreApi;

use \vendor\AwesomeApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
   public function whatever(): ClassOfVendor
        return new \mycompany\CutreApi\ClassOfVendor();

So seems that this errror raises also when you're using a method that return a namespaced class, and you try to return the same class but with other namespace. Fortunately I have found this solution, but I do not fully understand the benefit of this feature in php 7.2, for me it is normal to rewrite existing class methods as you need them, including the redefinition of input parameters and / or even behavior of the method.

One downside of the previous aproach, is that IDE's could not recognise the new methods implemented in \mycompany\CutreApi\ClassOfVendor(). So, for now, I will go with this implementation.

Currently done

namespace mycompany\CutreApi;

use mycompany\CutreApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
   public function getWhatever(): ClassOfVendor
        return new ClassOfVendor();

So, instead of trying to use "whatever" method, I wrote a new one called "getWhatever". In fact both of them are doing the same, just returning a class, but with diferents namespaces as I've described before.

Hope this can help someone.

convert iso date to milliseconds in javascript

Another possible solution is to compare current date with January 1, 1970, you can get January 1, 1970 by new Date(0);

var date = new Date(); 
var myDate= date - new Date(0);

How do I use a custom Serializer with Jackson?

If your only requirement in your custom serializer is to skip serializing the name field of User, mark it as transient. Jackson will not serialize or deserialize transient fields.

[ see also: Why does Java have transient fields? ]

Adding Google Play services version to your app's manifest?

In my case, I needed to copy the google-play-services_lib FOLDER in the same DRIVE of the source codes of my apps

  • F:\Products\Android\APP*.java <- My Apps are here so I copied to folder below
  • F:\Products\Android\libs\google-play-services_lib

How to convert an array to object in PHP?

You could also use an ArrayObject, for example:

    $arr = array("test",
    $o = new ArrayObject($arr);
    echo $o->offsetGet(2)["two"],"\n";
    foreach ($o as $key=>$val){
        if (is_array($val)) {
            foreach($val as $k => $v) {
               echo $k . ' => ' . $v,"\n";
               echo $val,"\n";

  one => 1
  two => 2
  three => 3
  one => 1
  two => 2
  three => 3

if statements matching multiple values

Is this what you are looking for ?

if (new int[] { 1, 2, 3, 4, 5 }.Contains(value))

Is mongodb running?

On Ubuntu (doc)

sudo systemctl status mongod

If running

? mongod.service - MongoDB Database Server
     Loaded: loaded (/lib/systemd/system/mongod.service; disabled; vendor preset: enabled)
     Active: active (running) since Wed 2020-10-14 14:13:40 UTC; 3s ago
   Main PID: 1604 (mongod)
     Memory: 210.8M
     CGroup: /system.slice/mongod.service
             +-1604 /usr/bin/mongod --config /etc/mongod.conf

If not running

? mongod.service - MongoDB Database Server
     Loaded: loaded (/lib/systemd/system/mongod.service; disabled; vendor preset: enabled)
     Active: inactive (dead)

To start mongodb

sudo systemctl start mongod

Use a content script to access the page context variables and functions

If you wish to inject pure function, instead of text, you can use this method:

function inject(){_x000D_ = 'blue';_x000D_
// this includes the function as text and the barentheses make it run itself._x000D_
var actualCode = "("+inject+")()"; _x000D_
document.documentElement.setAttribute('onreset', actualCode);_x000D_
document.documentElement.dispatchEvent(new CustomEvent('reset'));_x000D_

And you can pass parameters (unfortunatelly no objects and arrays can be stringifyed) to the functions. Add it into the baretheses, like so:

function inject(color){_x000D_ = color;_x000D_
// this includes the function as text and the barentheses make it run itself._x000D_
var color = 'yellow';_x000D_
var actualCode = "("+inject+")("+color+")"; 

How to convert an entire MySQL database characterset and collation to UTF-8?

You can create the sql to update all tables with:

    AS alter_sql
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = "your_database_name";

Capture the output and run it.

Arnold Daniels' answer above is more elegant.

JQuery .on() method with multiple event handlers to one selector

Also, if you had multiple event handlers attached to the same selector executing the same function, you could use

$('table.planning_grid').on('mouseenter mouseleave', function() {
    //JS Code

Mockito : how to verify method was called on an object created within a method?

Dependency Injection

If you inject the Bar instance, or a factory that is used for creating the Bar instance (or one of the other 483 ways of doing this), you'd have the access necessary to do perform the test.

Factory Example:

Given a Foo class written like this:

public class Foo {
  private BarFactory barFactory;

  public Foo(BarFactory factory) {
    this.barFactory = factory;

  public void foo() {
    Bar bar = this.barFactory.createBar();

in your test method you can inject a BarFactory like this:

public void testDoFoo() {
  Bar bar = mock(Bar.class);
  BarFactory myFactory = new BarFactory() {
    public Bar createBar() { return bar;}

  Foo foo = new Foo(myFactory);;

  verify(bar, times(1)).someMethod();

Bonus: This is an example of how TDD can drive the design of your code.

How to Validate Google reCaptcha on Form Submit

when using JavaScript it will work for me

<script src=''></script>_x000D_
function submitUserForm() {_x000D_
    var response = grecaptcha.getResponse();_x000D_
    if(response.length == 0) {_x000D_
        document.getElementById('g-recaptcha-error').innerHTML = '<span style="color:red;">This field is required.</span>';_x000D_
        return false;_x000D_
    return true;_x000D_
function verifyCaptcha() {_x000D_
    document.getElementById('g-recaptcha-error').innerHTML = '';_x000D_
<form method="post" onsubmit="return submitUserForm();">_x000D_
    <div class="g-recaptcha" data-sitekey="YOUR_SITE_KEY" data-callback="verifyCaptcha"></div>_x000D_
    <div id="g-recaptcha-error"></div>_x000D_
    <input type="submit" name="submit" value="Submit" />_x000D_

Generating all permutations of a given string

import java.util.ArrayList;
import java.util.Scanner;
public class hello {
    public static void main(String[] args) throws IOException {
        hello h = new hello();
      int fact=1;
    public void factrec(int a,int k){
        {System.out.println("The string  will have "+fact+" permutations");
    public void printcomp(){
        String str;
        int k;
        Scanner in = new Scanner(;
        System.out.println("enter the string whose permutations has to b found");;
        String[] arr =new String[fact];
        char[] array = str.toCharArray();
            // if incase u need array containing all the permutation use this
            //for(int d=0;d<fact;d++)         
    int y=1;
    int p = 0;
    int g=1;
    int z = 0;
    public void printcomprec(int k,char array[],String arr[]){
        for (int l = 0; l < k; l++) {
            for (int b=0;b<k-1;b++){
            for (int i=1; i<k-g; i++) {
                char temp;
                String stri = "";
                temp = array[i];
                array[i] = array[i + g];
                array[i + g] = temp;
                for (int j = 0; j < k; j++)
                    stri += array[j];
                arr[z] = stri;
                System.out.println(arr[z] + "   " + p++);
            char temp;
            if (y >= k-1)
        if (g >= k-1)


What are all the user accounts for IIS/ASP.NET and how do they differ?

This is a very good question and sadly many developers don't ask enough questions about IIS/ASP.NET security in the context of being a web developer and setting up IIS. So here goes....

To cover the identities listed:


This is analogous to the old IIS6 IIS_WPG group. It's a built-in group with it's security configured such that any member of this group can act as an application pool identity.


This account is analogous to the old IUSR_<MACHINE_NAME> local account that was the default anonymous user for IIS5 and IIS6 websites (i.e. the one configured via the Directory Security tab of a site's properties).

For more information about IIS_IUSRS and IUSR see:

Understanding Built-In User and Group Accounts in IIS 7


If an application pool is configured to run using the Application Pool Identity feature then a "synthesised" account called IIS AppPool\<pool name> will be created on the fly to used as the pool identity. In this case there will be a synthesised account called IIS AppPool\DefaultAppPool created for the life time of the pool. If you delete the pool then this account will no longer exist. When applying permissions to files and folders these must be added using IIS AppPool\<pool name>. You also won't see these pool accounts in your computers User Manager. See the following for more information:

Application Pool Identities

ASP.NET v4.0: -

This will be the Application Pool Identity for the ASP.NET v4.0 Application Pool. See DefaultAppPool above.


The NETWORK SERVICE account is a built-in identity introduced on Windows 2003. NETWORK SERVICE is a low privileged account under which you can run your application pools and websites. A website running in a Windows 2003 pool can still impersonate the site's anonymous account (IUSR_ or whatever you configured as the anonymous identity).

In ASP.NET prior to Windows 2008 you could have ASP.NET execute requests under the Application Pool account (usually NETWORK SERVICE). Alternatively you could configure ASP.NET to impersonate the site's anonymous account via the <identity impersonate="true" /> setting in web.config file locally (if that setting is locked then it would need to be done by an admin in the machine.config file).

Setting <identity impersonate="true"> is common in shared hosting environments where shared application pools are used (in conjunction with partial trust settings to prevent unwinding of the impersonated account).

In IIS7.x/ASP.NET impersonation control is now configured via the Authentication configuration feature of a site. So you can configure to run as the pool identity, IUSR or a specific custom anonymous account.


The LOCAL SERVICE account is a built-in account used by the service control manager. It has a minimum set of privileges on the local computer. It has a fairly limited scope of use:

LocalService Account


You didn't ask about this one but I'm adding for completeness. This is a local built-in account. It has fairly extensive privileges and trust. You should never configure a website or application pool to run under this identity.

LocalSystem Account

In Practice:

In practice the preferred approach to securing a website (if the site gets its own application pool - which is the default for a new site in IIS7's MMC) is to run under Application Pool Identity. This means setting the site's Identity in its Application Pool's Advanced Settings to Application Pool Identity:

enter image description here

In the website you should then configure the Authentication feature:

enter image description here

Right click and edit the Anonymous Authentication entry:

enter image description here

Ensure that "Application pool identity" is selected:

enter image description here

When you come to apply file and folder permissions you grant the Application Pool identity whatever rights are required. For example if you are granting the application pool identity for the ASP.NET v4.0 pool permissions then you can either do this via Explorer:

enter image description here

Click the "Check Names" button:

enter image description here

Or you can do this using the ICACLS.EXE utility:

icacls c:\wwwroot\mysite /grant "IIS AppPool\ASP.NET v4.0":(CI)(OI)(M)

...or...if you site's application pool is called BobsCatPicBlogthen:

icacls c:\wwwroot\mysite /grant "IIS AppPool\BobsCatPicBlog":(CI)(OI)(M)

I hope this helps clear things up.


I just bumped into this excellent answer from 2009 which contains a bunch of useful information, well worth a read:

The difference between the 'Local System' account and the 'Network Service' account?

How to import csv file in PHP?




if(mysql_query("load data local infile '".$path."' INTO TABLE tbl_customer FIELDS TERMINATED BY ',' enclosed by '\"' LINES TERMINATED BY '\n' IGNORE 1 LINES (`location`, `maildropdate`,`contact_number`,`first_name`,`mname`,`lastname`,`suffix`,`address`,`city`,`state`,`zip`)"))

      echo "imported successfully";


echo "<br>"."Uploaded Successfully".$path;


look here for futher info

How to sleep the thread in node.js without affecting other threads?

When working with async functions or observables provided by 3rd party libraries, for example Cloud firestore, I've found functions the waitFor method shown below (TypeScript, but you get the idea...) to be helpful when you need to wait on some process to complete, but you don't want to have to embed callbacks within callbacks within callbacks nor risk an infinite loop.

This method is sort of similar to a while (!condition) sleep loop, but yields asynchronously and performs a test on the completion condition at regular intervals till true or timeout.

export const sleep = (ms: number) => {
    return new Promise(resolve => setTimeout(resolve, ms))
 * Wait until the condition tested in a function returns true, or until 
 * a timeout is exceeded.
 * @param interval The frenequency with which the boolean function contained in condition is called.
 * @param timeout  The maximum time to allow for booleanFunction to return true
 * @param booleanFunction:  A completion function to evaluate after each interval. waitFor will return true as soon as the completion function returns true.   
export const waitFor = async function (interval: number, timeout: number,
    booleanFunction: Function): Promise<boolean> {
    let elapsed = 1;
    if (booleanFunction()) return true;
    while (elapsed < timeout) {
        elapsed += interval;
        await sleep(interval);
        if (booleanFunction()) {
            return true;
    return false;

The say you have a long running process on your backend you want to complete before some other task is undertaken. For example if you have a function that totals a list of accounts, but you want to refresh the accounts from the backend before you calculate, you can do something like this:

async recalcAccountTotals() : number {
     this.accountService.refresh();   //start the async process.
     if (this.accounts.dirty) {
           let updateResult = await waitFor(100,2000,()=> {return !(this.accounts.dirty)})
 if(!updateResult) { 
      console.error("Account refresh timed out, recalc aborted");
      return NaN;
 return ... //calculate the account total. 

Find nearest latitude/longitude with an SQL query

| id | email                 | name    | location_lat | location_long |
| 7  | [email protected]        | rembo   | 23.0249256   |  72.5269697   |
| 25 | [email protected].      | Rajnis  | 23.0233221    | 72.5342112   |

$lat = 23.02350629;

$long = 72.53230239;

DB:: SELECT (" SELECT * FROM ( SELECT , ( ( ( acos( sin(( ". $ lat ." * pi() / 180)) * sin(( lat * pi() / 180)) + cos(( ". $ lat ." pi() / 180 )) * cos(( lat * pi() / 180)) * cos((( ". $ long ." - LONG) * pi() / 180))) ) * 180 / pi() ) * 60 * 1.1515 * 1.609344 ) as distance FROM users ) users WHERE distance <= 2");

How to create a HTML Cancel button that redirects to a URL

There is no button type cancel

To achieve cancel functionality I used DOM history

<button type="button" class="btn btn-primary" onclick="window.history.back();">Cancel</button>

For more details :

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

In case this is useful to anyone I had this same issue. I was bringing in a footer into a web page via jQuery. Inside that footer were some Google scripts for ads and retargeting. I had to move those scripts from the footer and place them directly in the page and that eliminated the notice.

How do I make an HTTP request in Swift?

For XCUITest to stop the test finishing before the async request completes use this (maybe reduce the 100 timeout):

func test_api() {
    let url = URL(string: "")!
    let exp = expectation(description: "Waiting for data")
    let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
        guard let data = data else { return }
        print(String(data: data, encoding: .utf8)!)
    XCTWaiter.wait(for: [exp], timeout: 100)

Location of my.cnf file on macOS

I checked in macOS Sierra, the homebrew installed MySql 5.7.12

The support files are located at


Just copy my-default.cnf as /etc/my.cnf or /etc/mysql/my.cnf and the configuration will be picked up on restart.

What is an NP-complete in computer science?

It's a class of problems where we must simulate every possibility to be sure we have the optimal solution.

There are a lot of good heuristics for some NP-Complete problems, but they are only an educated guess at best.

How to convert list of numpy arrays into single numpy array?

In general you can concatenate a whole sequence of arrays along any axis:

numpy.concatenate( LIST, axis=0 )

but you do have to worry about the shape and dimensionality of each array in the list (for a 2-dimensional 3x5 output, you need to ensure that they are all 2-dimensional n-by-5 arrays already). If you want to concatenate 1-dimensional arrays as the rows of a 2-dimensional output, you need to expand their dimensionality.

As Jorge's answer points out, there is also the function stack, introduced in numpy 1.10:

numpy.stack( LIST, axis=0 )

This takes the complementary approach: it creates a new view of each input array and adds an extra dimension (in this case, on the left, so each n-element 1D array becomes a 1-by-n 2D array) before concatenating. It will only work if all the input arrays have the same shape—even along the axis of concatenation.

vstack (or equivalently row_stack) is often an easier-to-use solution because it will take a sequence of 1- and/or 2-dimensional arrays and expand the dimensionality automatically where necessary and only where necessary, before concatenating the whole list together. Where a new dimension is required, it is added on the left. Again, you can concatenate a whole list at once without needing to iterate:

numpy.vstack( LIST )

This flexible behavior is also exhibited by the syntactic shortcut numpy.r_[ array1, ...., arrayN ] (note the square brackets). This is good for concatenating a few explicitly-named arrays but is no good for your situation because this syntax will not accept a sequence of arrays, like your LIST.

There is also an analogous function column_stack and shortcut c_[...], for horizontal (column-wise) stacking, as well as an almost-analogous function hstack—although for some reason the latter is less flexible (it is stricter about input arrays' dimensionality, and tries to concatenate 1-D arrays end-to-end instead of treating them as columns).

Finally, in the specific case of vertical stacking of 1-D arrays, the following also works:

numpy.array( LIST )

...because arrays can be constructed out of a sequence of other arrays, adding a new dimension to the beginning.

Serializing a list to JSON

There are two common ways of doing that with built-in JSON serializers:

  1. JavaScriptSerializer

    var serializer = new JavaScriptSerializer();
    return serializer.Serialize(TheList);
  2. DataContractJsonSerializer

    var serializer = new DataContractJsonSerializer(TheList.GetType());
    using (var stream = new MemoryStream())
        serializer.WriteObject(stream, TheList);
        using (var sr = new StreamReader(stream))
            return sr.ReadToEnd();

    Note, that this option requires definition of a data contract for your class:

    public class MyObjectInJson
       public long ObjectID {get;set;}
       public string ObjectInJson {get;set;}

Restart container within pod

kubectl exec -it POD_NAME -c CONTAINER_NAME bash - then kill 1

Assuming the container is run as root which is not recommended.

In my case when I changed the application config, I had to reboot the container which was used in a sidecar pattern, I would kill the PID for the spring boot application which is owned by the docker user.

global variable for all controller and views

In Laravel 5+, to set a variable just once and access it 'globally', I find it easiest to just add it as an attribute to the Request:

$request->attributes->add(['myVar' => $myVar]);

Then you can access it from any of your controllers using:

$myVar = $request->get('myVar');

and from any of your blades using:

{{ Request::get('myVar') }}

How to print to console when using Qt

"build & run" > Default for "Run in terminal" --> Enable

to flush the buffer use this command --> fflush(stdout); you can also use "\n" in printf or cout.

Log4net does not write the log in the log file

Make sure the following line code should be there in AssemblyInfo.cs file.

[assembly: log4net.Config.XmlConfigurator(ConfigFile = "Web.config", Watch = true)]

and also check for this line in Application_start() method.


Creating and throwing new exception

You can throw your own custom errors by extending the Exception class.

class CustomException : Exception {
    [string] $additionalData

    CustomException($Message, $additionalData) : base($Message) {
        $this.additionalData = $additionalData

try {
    throw [CustomException]::new('Error message', 'Extra data')
} catch [CustomException] {
    # NOTE: To access your custom exception you must use $_.Exception
    Write-Output $_.Exception.additionalData

    # This will produce the error message: Didn't catch it the second time
    throw [CustomException]::new("Didn't catch it the second time", 'Extra data')

must appear in the GROUP BY clause or be used in an aggregate function

The problem with specifying non-grouped and non-aggregate fields in group by selects is that engine has no way of knowing which record's field it should return in this case. Is it first? Is it last? There is usually no record that naturally corresponds to aggregated result (min and max are exceptions).

However, there is a workaround: make the required field aggregated as well. In posgres, this should work:

SELECT cname, (array_agg(wmname ORDER BY avg DESC))[1], MAX(avg)
FROM makerar GROUP BY cname;

Note that this creates an array of all wnames, ordered by avg, and returns the first element (arrays in postgres are 1-based).

What is the non-jQuery equivalent of '$(document).ready()'?

In plain vanilla JavaScript, with no libraries? It's an error. $ is simply an identifier, and is undefined unless you define it.

jQuery defines $ as it's own "everything object" (also known as jQuery so you can use it without conflicting with other libraries). If you're not using jQuery (or some other library that defines it), then $ will not be defined.

Or are you asking what the equivalent is in plain JavaScript? In that case, you probably want window.onload, which isn't exactly equivalent, but is the quickest and easiest way to get close to the same effect in vanilla JavaScript.

Write lines of text to a file in R

What's about a simple writeLines()?

txt <- "Hallo\nWorld"
writeLines(txt, "outfile.txt")


txt <- c("Hallo", "World")
writeLines(txt, "outfile.txt")

How to get just numeric part of CSS property with jQuery?

parseint will truncate any decimal values (e.g. 1.5em gives 1).

Try a replace function with regex e.g.


Update Top 1 record in table sql server

It also works well ...

Update t
Set t.TIMESTAMP2 = '2013-12-12 15:40:31.593'
    Select Top 1 TIMESTAMP2
    From TX_Master_PCBA
    Where SERIAL_NO IN ('0500030309')
) t

Does Python have a string 'contains' substring method?

If you are happy with "blah" in somestring but want it to be a function/method call, you can probably do this

import operator

if not operator.contains(somestring, "blah"):

All operators in Python can be more or less found in the operator module including in.

anaconda update all possible packages?

Imagine the dependency graph of packages, when the number of packages grows large, the chance of encountering a conflict when upgrading/adding packages is much higher. To avoid this, simply create a new environment in Anaconda.

Be frugal, install only what you need. For me, I installed the following packages in my new environment:

  • pandas
  • scikit-learn
  • matplotlib
  • notebook
  • keras

And I have 84 packages in total.

How to convert text to binary code in JavaScript?

Just a hint into the right direction

var foo = "TEST",
    res = [ ];

foo.split('').forEach(function( letter ) {
    var bin     = letter.charCodeAt( 0 ).toString( 2 ),
        padding = 8 - bin.length;

    res.push( new Array( padding+1 ).join( '0' ) + bin );

console.log( res );

Static method in a generic class?

I ran into this same problem. I found my answer by downloading the source code for Collections.sort in the java framework. The answer I used was to put the <T> generic in the method, not in the class definition.

So this worked:

public class QuickSortArray  {
    public static <T extends Comparable> void quickSort(T[] array, int bottom, int top){
//do it


Of course, after reading the answers above I realized that this would be an acceptable alternative without using a generic class:

public static void quickSort(Comparable[] array, int bottom, int top){
//do it

PHP strtotime +1 month adding an extra month

 $endOfCycle = date("Y-m", mktime(0, 0, 0, date("m", time())+1 , 15, date("m", time())));

Plot 3D data in R

If you're working with "real" data for which the grid intervals and sequence cannot be guaranteed to be increasing or unique (hopefully the (x,y,z) combinations are unique at least, even if these triples are duplicated), I would recommend the akima package for interpolating from an irregular grid to a regular one.

Using your definition of data:

im <- with(data,interp(x,y,z))

enter image description here

And this should work not only with image but similar functions as well.

Note that the default grid to which your data is mapped to by akima::interp is defined by 40 equal intervals spanning the range of x and y values:

> formals(akima::interp)[c("xo","yo")]
seq(min(x), max(x), length = 40)

seq(min(y), max(y), length = 40)

But of course, this can be overridden by passing arguments xo and yo to akima::interp.

Verifying a specific parameter with Moq

I believe that the problem in the fact that Moq will check for equality. And, since XmlElement does not override Equals, it's implementation will check for reference equality.

Can't you use a custom object, so you can override equals?

Getting last month's date in php

$lastMonth = date('M Y', strtotime("-1 month"));
$lastMonth = date('M Y', mktime(0, 0, 0, date('m') - 1, 1, date('Y')));

Handling ExecuteScalar() when no results are returned

SQL NULL value

  • equivalent in C# is DBNull.Value
  • if a NULLABLE column has no value, this is what is returned
  • comparison in SQL: IF ( value IS NULL )
  • comparison in C#: if (obj == DBNull.Value)
  • visually represented in C# Quick-Watch as {}

Best practice when reading from a data reader:

var reader = cmd.ExecuteReader();
var result = (reader[i] == DBNull.Value ? "" : reader[i].ToString());

In my experience, there are some cases the returned value can be missing and thus execution fails by returning null. An example would be

select MAX(ID) from <table name> where <impossible condition>

The above script cannot find anything to find a MAX in. So it fails. In these such cases we must compare the old fashion way (compare with C# null)

var obj = cmd.ExecuteScalar();
var result = (obj == null ? -1 : Convert.ToInt32(obj));

When should I write the keyword 'inline' for a function/method?

Inline keyword requests the compiler to replace the function call with the body of the function ,it first evaluates the expression and then passed.It reduces the function call overhead as there is no need to store the return address and stack memory is not required for function arguments.

When to use:

  • To Improve performance
  • To reduce call overhead .
  • As it's just a request to the compiler, certain functions won't be inlined *large functions
    • functions having too many conditional arguments
    • recursive code and code with loops etc.

The character encoding of the plain text document was not declared - mootool script

For HTML5:

Simply add to your <head>

 <meta charset="UTF-8"> 

Use of Greater Than Symbol in XML

CDATA is a better general solution.

How can I generate Unix timestamps?

If I want to print utc date time using date command I need to using -u argument with date command.


date -u


Fri Jun 14 09:00:42 UTC 2019

How to get only the date value from a Windows Forms DateTimePicker control?

You mean how to get date without the time component? Use DateTimePicker.Value.Date But you need to format the output to your needs.

What is the difference between =Empty and IsEmpty() in VBA (Excel)?

Empty refers to a variable being at its default value. So if you check if a cell with a value of 0 = Empty then it would return true.

IsEmpty refers to no value being initialized.

In a nutshell, if you want to see if a cell is empty (as in nothing exists in its value) then use IsEmpty. If you want to see if something is currently in its default value then use Empty.

C++ array initialization

Yes, this form of initialization is supported by all C++ compilers. It is a part of C++ language. In fact, it is an idiom that came to C++ from C language. In C language = { 0 } is an idiomatic universal zero-initializer. This is also almost the case in C++.

Since this initalizer is universal, for bool array you don't really need a different "syntax". 0 works as an initializer for bool type as well, so

bool myBoolArray[ARRAY_SIZE] = { 0 };

is guaranteed to initialize the entire array with false. As well as

char* myPtrArray[ARRAY_SIZE] = { 0 };

in guaranteed to initialize the whole array with null-pointers of type char *.

If you believe it improves readability, you can certainly use

bool myBoolArray[ARRAY_SIZE] = { false };
char* myPtrArray[ARRAY_SIZE] = { nullptr };

but the point is that = { 0 } variant gives you exactly the same result.

However, in C++ = { 0 } might not work for all types, like enum types, for example, which cannot be initialized with integral 0. But C++ supports the shorter form

T myArray[ARRAY_SIZE] = {};

i.e. just an empty pair of {}. This will default-initialize an array of any type (assuming the elements allow default initialization), which means that for basic (scalar) types the entire array will be properly zero-initialized.

Getting Java version at runtime

java.version is a system property that exists in every JVM. There are two possible formats for it:

  • Java 8 or lower: 1.6.0_23, 1.7.0, 1.7.0_80, 1.8.0_211
  • Java 9 or higher: 9.0.1, 11.0.4, 12, 12.0.1

Here is a trick to extract the major version: If it is a 1.x.y_z version string, extract the character at index 2 of the string. If it is a x.y.z version string, cut the string to its first dot character, if one exists.

private static int getVersion() {
    String version = System.getProperty("java.version");
    if(version.startsWith("1.")) {
        version = version.substring(2, 3);
    } else {
        int dot = version.indexOf(".");
        if(dot != -1) { version = version.substring(0, dot); }
    } return Integer.parseInt(version);

Now you can check the version much more comfortably:

if(getVersion() < 6) {
    // ...

What is the purpose of global.asax in

The root directory of a web application has a special significance and certain content can be present on in that folder. It can have a special file called as “Global.asax”. ASP.Net framework uses the content in the global.asax and creates a class at runtime which is inherited from HttpApplication. During the lifetime of an application, ASP.NET maintains a pool of Global.asax derived HttpApplication instances. When an application receives an http request, the ASP.Net page framework assigns one of these instances to process that request. That instance is responsible for managing the entire lifetime of the request it is assigned to and the instance can only be reused after the request has been completed when it is returned to the pool. The instance members in Global.asax cannot be used for sharing data across requests but static member can be. Global.asax can contain the event handlers of HttpApplication object and some other important methods which would execute at various points in a web application

Passing command line arguments to R CMD BATCH

Here's another way to process command line args, using R CMD BATCH. My approach, which builds on an earlier answer here, lets you specify arguments at the command line and, in your R script, give some or all of them default values.

Here's an R file, which I name test.R:

defaults <- list(a=1, b=c(1,1,1)) ## default values of any arguments we might pass

## parse each command arg, loading it into global environment
for (arg in commandArgs(TRUE))

## if any variable named in defaults doesn't exist, then create it
## with value from defaults
for (nm in names(defaults))
  assign(nm, mget(nm, ifnotfound=list(defaults[[nm]]))[[1]])


At the command line, if I type

R CMD BATCH --no-save --no-restore '--args a=2 b=c(2,5,6)' test.R

then within R we'll have a = 2 and b = c(2,5,6). But I could, say, omit b, and add in another argument c:

R CMD BATCH --no-save --no-restore '--args a=2 c="hello"' test.R

Then in R we'll have a = 2, b = c(1,1,1) (the default), and c = "hello".

Finally, for convenience we can wrap the R code in a function, as long as we're careful about the environment:

## defaults should be either NULL or a named list
parseCommandArgs <- function(defaults=NULL, envir=globalenv()) {
  for (arg in commandArgs(TRUE))
    eval(parse(text=arg), envir=envir)

  for (nm in names(defaults))
    assign(nm, mget(nm, ifnotfound=list(defaults[[nm]]), envir=envir)[[1]], pos=envir)

## example usage:
parseCommandArgs(list(a=1, b=c(1,1,1)))

What is better, adjacency lists or adjacency matrices for graph problems in C++?

It depends on what you're looking for.

With adjacency matrices you can answer fast to questions regarding if a specific edge between two vertices belongs to the graph, and you can also have quick insertions and deletions of edges. The downside is that you have to use excessive space, especially for graphs with many vertices, which is very inefficient especially if your graph is sparse.

On the other hand, with adjacency lists it is harder to check whether a given edge is in a graph, because you have to search through the appropriate list to find the edge, but they are more space efficient.

Generally though, adjacency lists are the right data structure for most applications of graphs.

Where's my JSON data in my incoming Django request?

request.POST is just a dictionary-like object, so just index into it with dict syntax.

Assuming your form field is fred, you could do something like this:

if 'fred' in request.POST:
    mydata = request.POST['fred']

Alternately, use a form object to deal with the POST data.

<code> vs <pre> vs <samp> for inline and block code snippets

Personally I'd use <code> because that's the most semantically correct. Then to differentiate between inline and block code I'd add a class either:

<code class="inlinecode"></code>

for inline code or:

<code class="codeblock"></code>

for code block. Depending on which is less common.

Usage of __slots__?

Slots are very useful for library calls to eliminate the "named method dispatch" when making function calls. This is mentioned in the SWIG documentation. For high performance libraries that want to reduce function overhead for commonly called functions using slots is much faster.

Now this may not be directly related to the OPs question. It is related more to building extensions than it does to using the slots syntax on an object. But it does help complete the picture for the usage of slots and some of the reasoning behind them.

Why Response.Redirect causes System.Threading.ThreadAbortException?

I had that problem too.

Try using Server.Transfer instead of Response.Redirect

Worked for me.

TypeError: $.browser is undefined

I placed the following html in my code and this cleared up the $.browser error

<script src=""></script>

Hope this helps u

Changes in import statement python3

To support both Python 2 and Python 3, use explicit relative imports as below. They are relative to the current module. They have been supported starting from 2.5.

from .sister import foo
from . import brother
from ..aunt import bar
from .. import uncle

Is it possible to specify condition in Count()?

You can also use the Pivot Keyword if you are using SQL 2005 or above

more info and from Technet

FROM @Users
    FOR Position
    IN (Manager, CEO, Employee)
) as p

Test Data Set

DECLARE @Users TABLE (Position VARCHAR(10))
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('CEO')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')

How do I see the extensions loaded by PHP?

      echo "<pre>";
      echo "<pre/>";

Plot correlation matrix using pandas

Try this function, which also displays variable names for the correlation matrix:

def plot_corr(df,size=10):
    '''Function plots a graphical correlation matrix for each pair of columns in the dataframe.

        df: pandas DataFrame
        size: vertical and horizontal size of the plot'''

    corr = df.corr()
    fig, ax = plt.subplots(figsize=(size, size))
    plt.xticks(range(len(corr.columns)), corr.columns);
    plt.yticks(range(len(corr.columns)), corr.columns);

Creating a new dictionary in Python

You can do this

x = {}
x['a'] = 1

No provider for TemplateRef! (NgIf ->TemplateRef)

You missed the * in front of NgIf (like we all have, dozens of times):

<div *ngIf="answer.accepted">&#10004;</div>

Without the *, Angular sees that the ngIf directive is being applied to the div element, but since there is no * or <template> tag, it is unable to locate a template, hence the error.

If you get this error with Angular v5:

Error: StaticInjectorError[TemplateRef]:
    NullInjectorError: No provider for TemplateRef!

You may have <template>...</template> in one or more of your component templates. Change/update the tag to <ng-template>...</ng-template>.

How do I get the entity that represents the current user in Symfony2?

In symfony >= 3.2, documentation states that:

An alternative way to get the current user in a controller is to type-hint the controller argument with UserInterface (and default it to null if being logged-in is optional):

use Symfony\Component\Security\Core\User\UserInterface\UserInterface;

public function indexAction(UserInterface $user = null)
    // $user is null when not logged-in or anon.

This is only recommended for experienced developers who don't extend from the Symfony base controller and don't use the ControllerTrait either. Otherwise, it's recommended to keep using the getUser() shortcut.

Blog post about it

Background color on input type=button :hover state sticks in IE

Try using the type attribute selector to find buttons (maybe this'll fix it too):

  background-color: #E3E1B8; 

  background-color: #46000D

TypeError: expected a character buffer object - while trying to save integer to textfile

Have you checked the docstring of write()? It says:

write(str) -> None. Write string str to file.

Note that due to buffering, flush() or close() may be needed before the file on disk reflects the data written.

So you need to convert y to str first.

Also note that the string will be written at the current position which will be at the end of the file, because you'll already have read the old value. Use to get to the beginning of the file.`

Edit: As for the IOError, this issue seems related. A cite from there:

For the modes where both read and writing (or appending) are allowed (those which include a "+" sign), the stream should be flushed (fflush) or repositioned (fseek, fsetpos, rewind) between either a reading operation followed by a writing operation or a writing operation followed by a reading operation.

So, I suggest you try and maybe the problem goes away.

Sorting a set of values

From a comment:

I want to sort each set.

That's easy. For any set s (or anything else iterable), sorted(s) returns a list of the elements of s in sorted order:

>>> s = set(['0.000000000', '0.009518000', '10.277200999', '0.030810999', '0.018384000', '4.918560000'])
>>> sorted(s)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '10.277200999', '4.918560000']

Note that sorted is giving you a list, not a set. That's because the whole point of a set, both in mathematics and in almost every programming language,* is that it's not ordered: the sets {1, 2} and {2, 1} are the same set.

You probably don't really want to sort those elements as strings, but as numbers (so 4.918560000 will come before 10.277200999 rather than after).

The best solution is most likely to store the numbers as numbers rather than strings in the first place. But if not, you just need to use a key function:

>>> sorted(s, key=float)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '4.918560000', '10.277200999']

For more information, see the Sorting HOWTO in the official docs.

* See the comments for exceptions.

Find object by id in an array of JavaScript objects

Iterate over any item in the array. For every item you visit, check that item's id. If it's a match, return it.

If you just want teh codez:

function getId(array, id) {
    for (var i = 0, len = array.length; i < len; i++) {
        if (array[i].id === id) {
            return array[i];
    return null; // Nothing found

And the same thing using ECMAScript 5's Array methods:

function getId(array, id) {
    var obj = array.filter(function (val) {
        return === id;

    // Filter returns an array, and we just want the matching item.
    return obj[0];

How do I call a JavaScript function on page load?

Another way to do this is by using event listeners, here how you use them:

document.addEventListener("DOMContentLoaded", function() {


DOMContentLoaded It means when the DOM Objects of the document are fully loaded and seen by JavaScript, also this could have been "click", "focus"...

function() Anonymous function, will be invoked when the event occurs.

Oracle "(+)" Operator

The (+) operator indicates an outer join. This means that Oracle will still return records from the other side of the join even when there is no match. For example if a and b are emp and dept and you can have employees unassigned to a department then the following statement will return details of all employees whether or not they've been assigned to a department.

select * from emp, dept where emp.dept_id=dept.dept_id(+)

So in short, removing the (+) may make a significance difference but you might not notice for a while depending on your data!

Print all day-dates between two dates

import datetime

d1 =,8,15)
d2 =,9,15)
diff = d2 - d1
for i in range(diff.days + 1):
    print (d1 + datetime.timedelta(i)).isoformat()

Where does Jenkins store configuration files for the jobs it runs?

The best approach would be to keep your job configurations in a Jenkinsfile that live in source control.

How could I create a list in c++?

You should really use the standard List class. Unless, of course, this is a homework question, or you want to know how lists are implemented by STL.

You'll find plenty of simple tutorials via google, like this one. If you want to know how linked lists work "under the hood", try searching for C list examples/tutorials rather than C++.

Convert a bitmap into a byte array

You can also just Marshal.Copy the bitmap data. No intermediary memorystream etc. and a fast memory copy. This should work on both 24-bit and 32-bit bitmaps.

public static byte[] BitmapToByteArray(Bitmap bitmap)

    BitmapData bmpdata = null;

        bmpdata = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
        int numbytes = bmpdata.Stride * bitmap.Height;
        byte[] bytedata = new byte[numbytes];
        IntPtr ptr = bmpdata.Scan0;

        Marshal.Copy(ptr, bytedata, 0, numbytes);

        return bytedata;
        if (bmpdata != null)



How can I make a menubar fixed on the top while scrolling

 #header {

    #content {

Create a Cumulative Sum Column in MySQL

Using a correlated query:

         (SELECT SUM(x.count)
            FROM TABLE x
           WHERE <= AS cumulative_sum

Using MySQL variables:

         @running_total := @running_total + t.count AS cumulative_sum
    JOIN (SELECT @running_total := 0) r


  • The JOIN (SELECT @running_total := 0) r is a cross join, and allows for variable declaration without requiring a separate SET command.
  • The table alias, r, is required by MySQL for any subquery/derived table/inline view


  • MySQL specific; not portable to other databases
  • The ORDER BY is important; it ensures the order matches the OP and can have larger implications for more complicated variable usage (IE: psuedo ROW_NUMBER/RANK functionality, which MySQL lacks)

How can I create an object based on an interface file definition in TypeScript?

If you are using React, the parser will choke on the traditional cast syntax so an alternative was introduced for use in .tsx files

let a = {} as MyInterface;

Difference between 2 dates in seconds

$timeFirst  = strtotime('2011-05-12 18:20:20');
$timeSecond = strtotime('2011-05-13 18:20:20');
$differenceInSeconds = $timeSecond - $timeFirst;

You will then be able to use the seconds to find minutes, hours, days, etc.

getting the reason why websockets closed with close code 1006

In my and possibly @BIOHAZARD case it was nginx proxy timeout. In default it's 60 sec without activity in socket

I changed it to 24h in nginx and it resolved problem

proxy_read_timeout 86400s;
proxy_send_timeout 86400s;

jQuery "on create" event for dynamically-created elements

create a <select> with id , append it to document.. and call .combobox

  var dynamicScript='<select id="selectid"><option value="1">...</option>.....</select>'
  $('body').append(dynamicScript); //append this to the place your wanted.
  $('#selectid').combobox();  //get the id and add .combobox();

this should do the trick.. you can hide the select if you want and after .combobox show it..or else use find..

 $(document).find('select').combobox() //though this is not good performancewise

Split string into individual words Java

Yet another method, using StringTokenizer :

String s = "I want to walk my dog";
StringTokenizer tokenizer = new StringTokenizer(s);

while(tokenizer.hasMoreTokens()) {

How can I split a delimited string into an array in PHP?

Use explode() or preg_split() function to split the string in php with given delimiter

// Use preg_split() function 
$string = "123,456,78,000";  
$str_arr = preg_split ("/\,/", $string);  
// use of explode 
$string = "123,46,78,000"; 
$str_arr = explode (",", $string);  

Laravel - Route::resource vs Route::controller

RESTful Resource controller

A RESTful resource controller sets up some default routes for you and even names them.

Route::resource('users', 'UsersController');

Gives you these named routes:

Verb          Path                        Action  Route Name
GET           /users                      index   users.index
GET           /users/create               create  users.create
POST          /users                      store
GET           /users/{user}               show
GET           /users/{user}/edit          edit    users.edit
PUT|PATCH     /users/{user}               update  users.update
DELETE        /users/{user}               destroy users.destroy

And you would set up your controller something like this (actions = methods)

class UsersController extends BaseController {

    public function index() {}

    public function show($id) {}

    public function store() {}


You can also choose what actions are included or excluded like this:

Route::resource('users', 'UsersController', [
    'only' => ['index', 'show']

Route::resource('monkeys', 'MonkeysController', [
    'except' => ['edit', 'create']

API Resource controller

Laravel 5.5 added another method for dealing with routes for resource controllers. API Resource Controller acts exactly like shown above, but does not register create and edit routes. It is meant to be used for ease of mapping routes used in RESTful APIs - where you typically do not have any kind of data located in create nor edit methods.

Route::apiResource('users', 'UsersController');

RESTful Resource Controller documentation

Implicit controller

An Implicit controller is more flexible. You get routed to your controller methods based on the HTTP request type and name. However, you don't have route names defined for you and it will catch all subfolders for the same route.

Route::controller('users', 'UserController');

Would lead you to set up the controller with a sort of RESTful naming scheme:

class UserController extends BaseController {

    public function getIndex()
        // GET request to index

    public function getShow($id)
        // get request to 'users/show/{id}'

    public function postStore()
        // POST request to 'users/store'


Implicit Controller documentation

It is good practice to use what you need, as per your preference. I personally don't like the Implicit controllers, because they can be messy, don't provide names and can be confusing when using php artisan routes. I typically use RESTful Resource controllers in combination with explicit routes.

List columns with indexes in PostgreSQL

Create some test data...

create table test (a int, b int, c int, constraint pk_test primary key(a, b));
create table test2 (a int, b int, c int, constraint uk_test2 unique (b, c));
create table test3 (a int, b int, c int, constraint uk_test3b unique (b), constraint uk_test3c unique (c),constraint uk_test3ab unique (a, b));

List indexes and columns indexed:

    t.relname as table_name,
    i.relname as index_name,
    a.attname as column_name
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
order by

 table_name | index_name | column_name
 test       | pk_test    | a
 test       | pk_test    | b
 test2      | uk_test2   | b
 test2      | uk_test2   | c
 test3      | uk_test3ab | a
 test3      | uk_test3ab | b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

Roll up the column names:

    t.relname as table_name,
    i.relname as index_name,
    array_to_string(array_agg(a.attname), ', ') as column_names
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
group by
order by

 table_name | index_name | column_names
 test       | pk_test    | a, b
 test2      | uk_test2   | b, c
 test3      | uk_test3ab | a, b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

How to conditional format based on multiple specific text in Excel

You can use MATCH for instance.

  1. Select the column from the first cell, for example cell A2 to cell A100 and insert a conditional formatting, using 'New Rule...' and the option to conditional format based on a formula.

  2. In the entry box, put:

    =MATCH(A2, 'Sheet2'!A:A, 0)
  3. Pick the desired formatting (change the font to red or fill the cell background, etc) and click OK.

MATCH takes the value A2 from your data table, looks into 'Sheet2'!A:A and if there's an exact match (that's why there's a 0 at the end), then it'll return the row number.

Note: Conditional formatting based on conditions from other sheets is available only on Excel 2010 onwards. If you're working on an earlier version, you might want to get the list of 'Don't check' in the same sheet.

EDIT: As per new information, you will have to use some reverse matching. Instead of the above formula, try:

=SUM(IFERROR(SEARCH('Sheet2'!$A$1:$A$44, A2),0))

How can I implement a theme from bootswatch or wrapbootstrap in an MVC 5 project?

Bootswatch is a good alternative, but you can also find multiple types of free templates made for ASP.NET MVC that use MDBootstrap (a front-end framework built on top of Bootstrap) here:


Timeout jQuery effects

Update: As of jQuery 1.4 you can use the .delay( n ) method.


Note: $.show() and $.hide() by default are not queued, so if you want to use $.delay() with them, you need to configure them that way:

    .show({duration: 0, queue: true})
    .hide({duration: 0, queue: true});

You could possibly use the Queue syntax, this might work:


var e = $('.notice'); 
  }, 2000 ); 


or you could be really ingenious and make a jQuery function to do it.


  jQuery.fn.idle = function(time)
      var o = $(this); 
         }, time);

which would ( in theory , working on memory here ) permit you do to this:


Variable's memory size in Python

Use sys.getsizeof to get the size of an object, in bytes.

>>> from sys import getsizeof
>>> a = 42
>>> getsizeof(a)
>>> a = 2**1000
>>> getsizeof(a)

Note that the size and layout of an object is purely implementation-specific. CPython, for example, may use totally different internal data structures than IronPython. So the size of an object may vary from implementation to implementation.

ArrayAdapter in android to create simple listview

But again main doubt why TextView resource id it needs?

Look at the constructor and the params.

public ArrayAdapter (Context context, int resource, int textViewResourceId, T[] objects)

Added in API level 1 Constructor


context The current context.

resource The resource ID for a layout file containing a layout to use when instantiating views.

textViewResourceId The id of the TextView within the layout resource to be populated objects The objects to represent in the ListView. refers to the id of text in android resource. So you need not have the one in your activity.

Here's the full list

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
        android.R.layout.simple_list_item_1,, values);

this refers to activity context

android.R.layout.simple_list_item_1 simple_list_item_1 is the layout in android.R.layout. refers to the android resource id.

values is a string array from the link you provided

How to update Android Studio automatically?

Here's the easiest way, as in snapshot, download the required file and install.enter image description here

Enable UTF-8 encoding for JavaScript

I too had this issue, I would copy the whole piece of code and put in Notepad, before pasting in Notepad, make sure you save the file type as ALL files and save the doc as utf-8 format. then you can paste your code and run, It should work. ?????? obiviously means unreadable characters.

Downloading Java JDK on Linux via wget is shown license page instead

Downloading Java from the command line has always been troublesome. What I have been doing reciently is to use FireFox (other browsers might work) to get a download started on my laptop, pause it (within the Downloads windows), use the "Copy Download Link" menu item of the context menu displayed for the downloading file. This URL can then be used on the Linux box to download the same file. I expect the URL has a short time to live. Ugly, but generally successful.

BASH Syntax error near unexpected token 'done'

Open new file named foobar

nano -w foobar

Input script

 while [ 0 = 0 ]; do
   echo "Press [CTRL+C] to stop.."
   sleep 1

Exit and save

CTRL+X then Y and Enter

Set script executable and run

chmod +x foobar

How to get the entire document HTML as a string?

I am using outerHTML for elements (the main <html> container), and XMLSerializer for anything else including <!DOCTYPE>, random comments outside the <html> container, or whatever else might be there. It seems that whitespace isn't preserved outside the <html> element, so I'm adding newlines by default with sep="\n".

function get_document_html(sep="\n") {_x000D_
    let html = "";_x000D_
    let xml = new XMLSerializer();_x000D_
    for (let n of document.childNodes) {_x000D_
        if (n.nodeType == Node.ELEMENT_NODE)_x000D_
            html += n.outerHTML + sep;_x000D_
            html += xml.serializeToString(n) + sep;_x000D_
    return html;_x000D_
console.log(get_document_html().slice(0, 200));

Eclipse does not highlight matching variables

Sometimes problems in your project build path can cause this, make sure you resolve it first, in my case the prolem was :

enter image description here

And when fix it highlights come back.

How to convert a string to JSON object in PHP

Try with json_encode().

And look again Valid JSON

/bin/sh: apt-get: not found

The image you're using is Alpine based, so you can't use apt-get because it's Ubuntu's package manager.

To fix this just use:

apk update and apk add

How do you clear a slice in Go?

I was looking into this issue a bit for my own purposes; I had a slice of structs (including some pointers) and I wanted to make sure I got it right; ended up on this thread, and wanted to share my results.

To practice, I did a little go playground:

which evals to this:

package main

import "fmt"

type Blah struct {
    babyKitten int
    kittenSays *string

func main() {
    meow := "meow"
    Blahs := []Blah{}
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{1, &meow})
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{2, &meow})
    fmt.Printf("Blahs: %v\n", Blahs)
    //fmt.Printf("kittenSays: %v\n", *Blahs[0].kittenSays)
    Blahs = nil
    meow2 := "nyan"
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{1, &meow2})
    fmt.Printf("Blahs: %v\n", Blahs)
    fmt.Printf("kittenSays: %v\n", *Blahs[0].kittenSays)

Running that code as-is will show the same memory address for both "meow" and "meow2" variables as being the same:

Blahs: []
Blahs: [{1 0x1030e0c0}]
Blahs: [{1 0x1030e0c0} {2 0x1030e0c0}]
Blahs: []
Blahs: [{1 0x1030e0f0}]
kittenSays: nyan

which I think confirms that the struct is garbage collected. Oddly enough, uncommenting the commented print line, will yield different memory addresses for the meows:

Blahs: []
Blahs: [{1 0x1030e0c0}]
Blahs: [{1 0x1030e0c0} {2 0x1030e0c0}]
kittenSays: meow
Blahs: []
Blahs: [{1 0x1030e0f8}]
kittenSays: nyan

I think this may be due to the print being deferred in some way (?), but interesting illustration of some memory mgmt behavior, and one more vote for:

[]MyStruct = nil

Why do I have to "git push --set-upstream origin <branch>"?

If you forgot to add the repository HTTPS link then put it with git push <repo HTTPS>

Decorators with parameters?

def decorator(argument):
    def real_decorator(function):
        def wrapper(*args):
            for arg in args:
                assert type(arg)==int,f'{arg} is not an interger'
            result = function(*args)
            result = result*argument
            return result
        return wrapper
    return real_decorator

Usage of the decorator

def adder(*args):
    for i in args:
    return sum

Then the







AssertionError                            Traceback (most recent call last)
<ipython-input-143-242a8feb1cc4> in <module>
----> 1 adder('hi',3)

<ipython-input-140-d3420c248ebd> in wrapper(*args)
      3         def wrapper(*args):
      4             for arg in args:
----> 5                 assert type(arg)==int,f'{arg} is not an interger'
      6             result = function(*args)
      7             result = result*argument

AssertionError: hi is not an interger

How to update single value inside specific array item in redux

Very late to the party but here is a generic solution that works with every index value.

  1. You create and spread new array from the old array up to the index you want to change.

  2. Add the data you want.

  3. Create and spread new array from the index you wanted to change to the end of the array

let index=1;// probabbly
   return { 
       contents: [
          {title: "some other title", text: "some other text"},


I have made a small module to simplify the code, so you just need to call a function:

   return {
       contents: insertIntoArray(state.contents,index, {title: "some title", text: "some text"})

For more examples, take a look at the repository

function signature:


Proper way of checking if row exists in table in PL/SQL block

If you are using an explicit cursor, It should be as follows.

   CURSOR get_id IS 
    SELECT id 
      FROM person 
      WHERE id = 10;

   OPEN get_id;
   FETCH get_id INTO id_value_;

   IF (get_id%FOUND) THEN
     DBMS_OUTPUT.PUT_LINE('Record Found.');
     DBMS_OUTPUT.PUT_LINE('Record Not Found.');
   END IF;
   CLOSE get_id;

  WHEN no_data_found THEN
  --do things when record doesn't exist

Mockito verify order / sequence of method calls

With BDD it's

public void testOrderWithBDD() {

    // Given
    ServiceClassA firstMock = mock(ServiceClassA.class);
    ServiceClassB secondMock = mock(ServiceClassB.class);

    //create inOrder object passing any mocks that need to be verified in order
    InOrder inOrder = inOrder(firstMock, secondMock);


    // When

    // Then


How to write macro for Notepad++?

I just did this in v5.9.1. Just go to the Macro Menu, click "Start Recording", perform your 3 replace all commands, then stop recording. You can then select "Save Current Recorded Macro", and play it back as often as you like, and it will perform the replaces as you expect.

6 digits regular expression

^[0-9]{1,6}$ should do it. I don't know VB.NET good enough to know if it's the same there.

For examples, have a look at the Wikipedia.

How to wait until an element exists?

You can try this:

const wait_until_element_appear = setInterval(() => {
    if ($(element).length !== 0) {
        // some code
}, 0);

This solution works very good for me

Android: How to set password property in an edit text?

My search for a similar solution for Visual Studio 2015/Xamarin lead me to this thread. While setting the EditText.InputType to Android.Text.InputTypes.TextVariationVisiblePassword properly hid the password during user entry, it did not 'hide' the password if it was visible before the EditText Layout was rendered (before the user submitted their password entry). In order to hide a visible password after the user submits their password and the EditText Layout is rendered, I used EditText.TransformationMethod = PasswordTransformationMethod.Instance as suggested by LuxuryMode.

How to correctly display .csv files within Excel 2013?

I know that an answer has already been accepted, but one item to check is the encoding of the CSV file. I have a Powershell script that generates CSV files. By default, it was encoding them as UCS-2 Little Endian (per Notepad++). It would open the file in a single column in Excel and I'd have to do the Text to Columns conversion to split the columns. Changing the script to encode the same output as "ASCII" (UTF-8 w/o BOM per Notepad++) allowed me to open the CSV directly with the columns split out. You can change the encoding of the CSV in Notepad++ too.

  • Menu Encoding > Convert to UTF-8 without BOM
  • Save the CSV file
  • Open in Excel, columns should be split

How to download/checkout a project from Google Code in Windows?

If you don't want to install anything but do want to download an SVN or GIT repository, then you can use this:

I have nothing to do with this project, but I just used it now and it saved me a few minutes. Maybe it will help someone.

Can an Android Toast be longer than Toast.LENGTH_LONG?

If you need a long Toast, there's a practical alternative, but it requires your user to click on an OK button to make it go away. You can use an AlertDialog like this:

String message = "This is your message";
new AlertDialog.Builder(YourActivityName.this)
    .setTitle("Optional Title (you can omit this)")
    .setPositiveButton("ok", null)

If you have a long message, chances are, you don't know how long it will take for your user to read the message, so sometimes it is a good idea to require your user to click on an OK button to continue. In my case, I use this technique when a user clicks on a help icon.

Java: Enum parameter in method

I like this a lot better. reduces the if/switch, just do.

private enum Alignment { LEFT, RIGHT;

void process() {
//Process it...
String drawCellValue (int maxCellLength, String cellValue, Alignment align){

of course, it can be:

String process(...) {
//Process it...

javascript create array from for loop

even shorter if you can lose the yearStart value:

var yearStart = 2000;
var yearEnd = 2040;

var arr = [];

while(yearStart < yearEnd+1){

UPDATE: If you can use the ES6 syntax you can do it the way proposed here:

let yearStart = 2000;
let yearEnd = 2040;
let years = Array(yearEnd-yearStart+1)
    .map(() => yearStart++);

ToList().ForEach in Linq

Try this:

foreach (var dept in employees.SelectMany(e => e.Departments))
   dept.SomeProperty = null;

How set background drawable programmatically in Android

I'm using a minSdkVersion 16 and targetSdkVersion 23.
The following is working for me, it uses

ContextCompat.getDrawable(context, R.drawable.drawable);

Instead of using:


Rather use:

layout.setBackground(ContextCompat.getDrawable(this, R.drawable.ready));

getActivity() is used in a fragment, if calling from a activity use this.

Bulk insert with SQLAlchemy ORM

As far as I know, there is no way to get the ORM to issue bulk inserts. I believe the underlying reason is that SQLAlchemy needs to keep track of each object's identity (i.e., new primary keys), and bulk inserts interfere with that. For example, assuming your foo table contains an id column and is mapped to a Foo class:

x = Foo(bar=1)
# None
# INSERT INTO foo (bar) VALUES(1)
# 1

Since SQLAlchemy picked up the value for without issuing another query, we can infer that it got the value directly from the INSERT statement. If you don't need subsequent access to the created objects via the same instances, you can skip the ORM layer for your insert:

Foo.__table__.insert().execute([{'bar': 1}, {'bar': 2}, {'bar': 3}])
# INSERT INTO foo (bar) VALUES ((1,), (2,), (3,))

SQLAlchemy can't match these new rows with any existing objects, so you'll have to query them anew for any subsequent operations.

As far as stale data is concerned, it's helpful to remember that the session has no built-in way to know when the database is changed outside of the session. In order to access externally modified data through existing instances, the instances must be marked as expired. This happens by default on session.commit(), but can be done manually by calling session.expire_all() or session.expire(instance). An example (SQL omitted):

x = Foo(bar=1)
# 1
# 1
# 42

session.commit() expires x, so the first print statement implicitly opens a new transaction and re-queries x's attributes. If you comment out the first print statement, you'll notice that the second one now picks up the correct value, because the new query isn't emitted until after the update.

This makes sense from the point of view of transactional isolation - you should only pick up external modifications between transactions. If this is causing you trouble, I'd suggest clarifying or re-thinking your application's transaction boundaries instead of immediately reaching for session.expire_all().

java.lang.ClassNotFoundException on working app

Setting minifyEnabled to false in my build.gradle file fixed the issue for me.

release {
    minifyEnabled false

Position DIV relative to another DIV?

You want to use position: absolute while inside the other div.


UML diagram shapes missing on Visio 2013

Microsoft is moving away from software and database diagramming using Visio and instead transitioning into Visual Studio. See the "Modeling" Projects. Component Diagrams, Sequence Diagrams, Use Cases, Layer Diagrams are all part of the modeling project. While I am experimenting with it (but question its viability), you can generate code from the models creating in the code generation sense.

See also this post Pet Shop Models as well as the MSDN documentation: Modeling the Architectural

Here's what I have available in vs2013 ultimate Pet Shop Project

Measuring execution time of a function in C++

If you want to safe time and lines of code you can make measuring the function execution time a one line macro:

a) Implement a time measuring class as already suggested above ( here is my implementation for android):

class MeasureExecutionTime{
    const std::chrono::steady_clock::time_point begin;
    const std::string caller;
    MeasureExecutionTime(const std::string& caller):caller(caller),begin(std::chrono::steady_clock::now()){}
        const auto duration=std::chrono::steady_clock::now()-begin;
        LOGD("ExecutionTime")<<"For "<<caller<<" is "<<std::chrono::duration_cast<std::chrono::milliseconds>(duration).count()<<"ms";

b) Add a convenient macro that uses the current function name as TAG (using a macro here is important, else __FUNCTION__ will evaluate to MeasureExecutionTime instead of the function you wanto to measure

#define MEASURE_FUNCTION_EXECUTION_TIME const MeasureExecutionTime measureExecutionTime(__FUNCTION__);

c) Write your macro at the begin of the function you want to measure. Example:

 void DecodeMJPEGtoANativeWindowBuffer(uvc_frame_t* frame_mjpeg,const ANativeWindow_Buffer& nativeWindowBuffer){
        // Do some time-critical stuff 

Which will result int the following output:

ExecutionTime: For DecodeMJPEGtoANativeWindowBuffer is 54ms

Note that this (as all other suggested solutions) will measure the time between when your function was called and when it returned, not neccesarily the time your CPU was executing the function. However, if you don't give the scheduler any change to suspend your running code by calling sleep() or similar there is no difference between.

Disabling Strict Standards in PHP 5.4

It worked for me, when I set error_reporting in two places at same time

somewhere in PHP code

ini_set('error_reporting', 30711);

and in .htaccess file

php_value error_reporting 30711

How to call a web service from jQuery


The OP was not looking to use cross-domain requests, but jQuery supports JSONP as of v1.5. See jQuery.ajax(), specificically the crossDomain parameter.

The regular jQuery Ajax requests will not work cross-site, so if you want to query a remote RESTful web service, you'll probably have to make a proxy on your server and query that with a jQuery get request. See this site for an example.

If it's a SOAP web service, you may want to try the jqSOAPClient plugin.

Polynomial time and exponential time

Check this out.

Exponential is worse than polynomial.

O(n^2) falls into the quadratic category, which is a type of polynomial (the special case of the exponent being equal to 2) and better than exponential.

Exponential is much worse than polynomial. Look at how the functions grow

n    = 10    |     100   |      1000

n^2  = 100   |   10000   |   1000000 

k^n  = k^10  |   k^100   |    k^1000

k^1000 is exceptionally huge unless k is smaller than something like 1.1. Like, something like every particle in the universe would have to do 100 billion billion billion operations per second for trillions of billions of billions of years to get that done.

I didn't calculate it out, but ITS THAT BIG.

How to run html file using node js

Either you use a framework or you write your own server with nodejs.

A simple fileserver may look like this:

import * as http from 'http';
import * as url from 'url';
import * as fs from 'fs';
import * as path from 'path';

var mimeTypes = {
     "html": "text/html",
     "jpeg": "image/jpeg",
     "jpg": "image/jpeg",
     "png": "image/png",
     "js": "text/javascript",
     "css": "text/css"};

http.createServer((request, response)=>{
    var pathname = url.parse(request.url).pathname;
    var filename : string;
    if(pathname === "/"){
        filename = "index.html";
        filename = path.join(process.cwd(), pathname);

        fs.accessSync(filename, fs.F_OK);
        var fileStream = fs.createReadStream(filename);
        var mimeType = mimeTypes[path.extname(filename).split(".")[1]];
        response.writeHead(200, {'Content-Type':mimeType});
    catch(e) {
            console.log('File not exists: ' + filename);
            response.writeHead(404, {'Content-Type': 'text/plain'});
            response.write('404 Not Found\n');

Attempt to present UIViewController on UIViewController whose view is not in the window hierarchy

Sadly, the accepted solution did not work for my case. I was trying to navigate to a new View Controller right after unwind from another View Controller.

I found a solution by using a flag to indicate which unwind segue was called.

@IBAction func unwindFromAuthenticationWithSegue(segue: UIStoryboardSegue) {
    self.shouldSegueToMainTabBar = true

@IBAction func unwindFromForgetPasswordWithSegue(segue: UIStoryboardSegue) {
    self.shouldSegueToLogin = true

Then present the wanted VC with present(_ viewControllerToPresent: UIViewController)

override func viewWillAppear(_ animated: Bool) {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    if self.shouldSegueToMainTabBar {
        let mainTabBarController = storyboard.instantiateViewController(withIdentifier: "mainTabBarVC") as! MainTabBarController
        self.present(mainTabBarController, animated: true)
        self.shouldSegueToMainTabBar = false
    if self.shouldSegueToLogin {
        let loginController = storyboard.instantiateViewController(withIdentifier: "loginVC") as! LogInViewController
        self.present(loginController, animated: true)
        self.shouldSegueToLogin = false

Basically, the above code will let me catch the unwind from login/SignUp VC and navigate to the dashboard, or catch the unwind action from forget password VC and navigate to the login page.

How does the enhanced for statement work for arrays, and how to get an iterator for an array?

Google Guava Libraries collection provides such function:

Iterator<String> it = Iterators.forArray(array);

One should prefere Guava over the Apache Collection (which seems to be abandoned).

Python Decimals format

Just use Python's standard string formatting methods:

>>> "{0:.2}".format(1.234232)
>>> "{0:.3}".format(1.234232)

If you are using a Python version under 2.6, use

>>> "%f" % 1.32423
>>> "%.2f" % 1.32423
>>> "%d" % 1.32423

Angular.js directive dynamic templateURL

I had the same problem and I solved in a slightly different way from the others. I am using angular 1.4.4.

In my case, I have a shell template that creates a CSS Bootstrap panel:

<div class="class-container panel panel-info">
    <div class="panel-heading">
        <h3 class="panel-title">{{title}} </h3>
    <div class="panel-body">
        <sp-panel-body panelbodytpl="{{panelbodytpl}}"></sp-panel-body>

I want to include panel body templates depending on the route.

    .directive('spPanelBody', ['$compile', function($compile){
        return {
            restrict        : 'E',
            scope : true,
            link: function (scope, element, attrs) {
       = angular.fromJson(;
                element.append($compile('<ng-include src="\'' + scope.panelbodytpl + '\'"></ng-include>')(scope));

I then have the following template included when the route is #/students:

<div class="students-wrapper">
    <div ng-controller="StudentsIndexController as studentCtrl" class="row">
        <div ng-repeat="student in studentCtrl.students" class="col-sm-6 col-md-4 col-lg-3">
            title="{{student.firstName}} {{student.middleName}} {{student.lastName}}"

The panel-body.html template as follows:

Date of Birth: {{data.dob * 1000 | date : 'dd MMM yyyy'}}

Sample data in the case someone wants to have a go:

var student = {
    'id'            : 1,
    'firstName'     : 'John',
    'middleName'    : '',
    'lastName'      : 'Smith',
    'dob'           : 1130799600,
    'current-class' : 5

string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)

They are different functions. You should decide for your situation what do you need.

I don't consider using any of them as a bad practice. Most of the time IsNullOrEmpty() is enough. But you have the choice :)

Set variable value to array of strings

-- create test table "Accounts"
create table Accounts (
  c_ID int primary key
 ,first_name varchar(100)
 ,last_name varchar(100)
 ,city varchar(100)

insert into Accounts values (101, 'Sebastian', 'Volk', 'Frankfurt' );
insert into Accounts values (102, 'Beate',  'Mueller', 'Hamburg' );
insert into Accounts values (103, 'John',  'Walker', 'Washington' );
insert into Accounts values (104, 'Britney', 'Sears', 'Holywood' );
insert into Accounts values (105, 'Sarah', 'Schmidt', 'Mainz' );
insert into Accounts values (106, 'George', 'Lewis', 'New Jersey' );
insert into Accounts values (107, 'Jian-xin', 'Wang', 'Peking' );
insert into Accounts values (108, 'Katrina', 'Khan', 'Bolywood' );

-- declare table variable
declare @tb_FirstName table(name varchar(100));
insert into  @tb_FirstName values ('John'), ('Sarah'), ('George');

FROM Accounts
WHERE first_name in (select name from @tb_FirstName);

FROM Accounts
WHERE first_name not in (select name from @tb_FirstName);

drop table Accounts;

Can't create project on Netbeans 8.2

If you run in linux, open file netbeans.conf using nano or anything else.

nano netbeans-8.2/etc/netbeans.conf

and edit jdkhome or directory for jdk


you can check your jdk version with

java -version


ls /usr/lib/jvm

Match multiline text using regular expression

First, you're using the modifiers under an incorrect assumption.

Pattern.MULTILINE or (?m) tells Java to accept the anchors ^ and $ to match at the start and end of each line (otherwise they only match at the start/end of the entire string).

Pattern.DOTALL or (?s) tells Java to allow the dot to match newline characters, too.

Second, in your case, the regex fails because you're using the matches() method which expects the regex to match the entire string - which of course doesn't work since there are some characters left after (\\W)*(\\S)* have matched.

So if you're simply looking for a string that starts with User Comments:, use the regex

^\s*User Comments:\s*(.*)

with the Pattern.DOTALL option:

Pattern regex = Pattern.compile("^\\s*User Comments:\\s+(.*)", Pattern.DOTALL);
Matcher regexMatcher = regex.matcher(subjectString);
if (regexMatcher.find()) {
    ResultString =;

ResultString will then contain the text after User Comments:

Installing lxml module in python

If you are encountering this issue on an Alpine based image try this :

apk add --update --no-cache g++ gcc libxml2-dev libxslt-dev python-dev libffi-dev openssl-dev make

// pip install -r requirements.txt

Deleting an object in java?

Yea, java is Garbage collected, it will delete the memory for you.

[Ljava.lang.Object; cannot be cast to

In case entire entity is being return, better solution in spring JPA is use @Query(value = "from entity where Id in :ids")

This return entity type rather than object type

jQuery returning "parsererror" for ajax request

I had the same problem, turned out my web.config was not the same with my teammates. So please check your web.config.

Hope this helps someone.

How to create a hidden <img> in JavaScript?

How about

<img style="display: none;" src="a.gif">

That will disable the display completely, and not leave a placeholder

Accessing inventory host variable in Ansible playbook

I've found also a nice and simple way to address hostsvars right on one of Ansible's Github issues

Looks like you can do this as well:

 - debug:
    msg: "{{ ansible_ssh_host }}"

Vue.js dynamic images not working

You can try the require function. like this:

<img :src="require(`@/xxx/${name}.png`)" alt class="icon" />

How to update cursor limit for ORA-01000: maximum open cursors exceed

Assuming that you are using a spfile to start the database

alter system set open_cursors = 1000 scope=both;

If you are using a pfile instead, you can change the setting for the running instance

alter system set open_cursors = 1000 

You would also then need to edit the parameter file to specify the new open_cursors setting. It would generally be a good idea to restart the database shortly thereafter to make sure that the parameter file change works as expected (it's highly annoying to discover months later the next time that you reboot the database that some parameter file change than no one remembers wasn't done correctly).

I'm also hoping that you are certain that you actually need more than 300 open cursors per session. A large fraction of the time, people that are adjusting this setting actually have a cursor leak and they are simply trying to paper over the bug rather than addressing the root cause.

PHP is not recognized as an internal or external command in command prompt

You need to Go to My Computer->properties -> Advanced system setting

Now click on Environment Variables..

enter image description here

Add ;C:\xampp\php in path variable value

enter image description here

Now restart command prompt DONE!

Note: Make sure you run CMD via run as administrator

jquery $('.class').each() how many items?

If you are using a version of jQuery that is less than version 1.8 you can use the $('.class').size() which takes zero parameters. See documentation for more information on .size() method.

However if you are using (or plan to upgrade) to 1.8 or greater you can use $('.class').length property. See documentation for more information on .length property.

How to find out what type of a Mat object is with Mat::type() in OpenCV

Here is a handy function you can use to help with identifying your opencv matrices at runtime. I find it useful for debugging, at least.

string type2str(int type) {
  string r;

  uchar depth = type & CV_MAT_DEPTH_MASK;
  uchar chans = 1 + (type >> CV_CN_SHIFT);

  switch ( depth ) {
    case CV_8U:  r = "8U"; break;
    case CV_8S:  r = "8S"; break;
    case CV_16U: r = "16U"; break;
    case CV_16S: r = "16S"; break;
    case CV_32S: r = "32S"; break;
    case CV_32F: r = "32F"; break;
    case CV_64F: r = "64F"; break;
    default:     r = "User"; break;

  r += "C";
  r += (chans+'0');

  return r;

If M is a var of type Mat you can call it like so:

string ty =  type2str( M.type() );
printf("Matrix: %s %dx%d \n", ty.c_str(), M.cols, M.rows );

Will output data such as:

Matrix: 8UC3 640x480 
Matrix: 64FC1 3x2 

Its worth noting that there are also Matrix methods Mat::depth() and Mat::channels(). This function is just a handy way of getting a human readable interpretation from the combination of those two values whose bits are all stored in the same value.

SoapFault exception: Could not connect to host

I hit this issue myself and after much digging I eventually found this bug for ubuntu:


openssl s_client -connect site.tld:443 failed however openssl s_client -tls1 -connect site.tld:443 gave success. In my particular case part of the output included New, TLSv1/SSLv3, Cipher is RC4-MD5 so I set the php context ssl/cipher value appropriately.

Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel

try using this one

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
Invoke-WebRequest -Uri

ORA-00918: column ambiguously defined in SELECT *

A query's projection can only have one instance of a given name. As your WHERE clause shows, you have several tables with a column called ID. Because you are selecting * your projection will have several columns called ID. Or it would have were it not for the compiler hurling ORA-00918.

The solution is quite simple: you will have to expand the projection to explicitly select named columns. Then you can either leave out the duplicate columns, retaining just (say) COACHES.ID or use column aliases: as COACHES_ID.

Perhaps that strikes you as a lot of typing, but it is the only way. If it is any comfort, SELECT * is regarded as bad practice in production code: explicitly named columns are much safer.

How to call a method after a delay in Android

I like things cleaner: Here is my implementation, inline code to use inside your method

new Handler().postDelayed(new Runnable() {
  public void run() {
    //Do something after 100ms
}, 100);

How to efficiently calculate a running standard deviation?

The basic answer is to accumulate the sum of both x (call it 'sum_x1') and x2 (call it 'sum_x2') as you go. The value of the standard deviation is then:

stdev = sqrt((sum_x2 / n) - (mean * mean)) 


mean = sum_x / n

This is the sample standard deviation; you get the population standard deviation using 'n' instead of 'n - 1' as the divisor.

You may need to worry about the numerical stability of taking the difference between two large numbers if you are dealing with large samples. Go to the external references in other answers (Wikipedia, etc) for more information.

Fastest way to check if a file exist using standard C++/C++11/C?

Another 3 options under windows:


inline bool exist(const std::string& name)
    OFSTRUCT of_struct;
    return OpenFile(name.c_str(), &of_struct, OF_EXIST) != INVALID_HANDLE_VALUE && of_struct.nErrCode == 0;


inline bool exist(const std::string& name)
    if (hFile != NULL && hFile != INVALID_HANDLE)
         return true;
    return false;


inline bool exist(const std::string& name)
    return GetFileAttributes(name.c_str()) != INVALID_FILE_ATTRIBUTES;

How to remove part of a string?

string = "removeTHISplease";
result = string.replace('THIS','');

I think replace do the same thing like a some own function. For me this works.

Reference to a non-shared member requires an object reference occurs when calling public sub

Go to the Declaration of the desired object and mark it Shared.

Friend Shared WithEvents MyGridCustomer As Janus.Windows.GridEX.GridEX

Generate a Hash from string in Javascript

Adding this because nobody did yet, and this seems to be asked for and implemented a lot with hashes, but it's always done very poorly...

This takes a string input, and a maximum number you want the hash to equal, and produces a unique number based on the string input.

You can use this to produce a unique index into an array of images (If you want to return a specific avatar for a user, chosen at random, but also chosen based on their name, so it will always be assigned to someone with that name).

You can also use this, of course, to return an index into an array of colors, like for generating unique avatar background colors based on someone's name.

function hashInt (str, max = 1000) {
    var hash = 0;
    for (var i = 0; i < str.length; i++) {
      hash = ((hash << 5) - hash) + str.charCodeAt(i);
      hash = hash & hash;
    return Math.round(max * Math.abs(hash) / 2147483648);

Find duplicate records in MongoDB

Use aggregation on name and get name with count > 1:

    {"$group" : { "_id": "$name", "count": { "$sum": 1 } } },
    {"$match": {"_id" :{ "$ne" : null } , "count" : {"$gt": 1} } }, 
    {"$project": {"name" : "$_id", "_id" : 0} }

To sort the results by most to least duplicates:

    {"$group" : { "_id": "$name", "count": { "$sum": 1 } } },
    {"$match": {"_id" :{ "$ne" : null } , "count" : {"$gt": 1} } }, 
    {"$sort": {"count" : -1} },
    {"$project": {"name" : "$_id", "_id" : 0} }     

To use with another column name than "name", change "$name" to "$column_name"