Programs & Examples On #Javascript

JavaScript (not to be confused with Java) is a high-level, dynamic, multi-paradigm, weakly-typed language used for both client-side and server-side scripting. Its primary use is in rendering and allowing manipulation of web pages. Use this tag for questions regarding ECMAScript and its various dialects/implementations (excluding ActionScript and Google-Apps-Script).

Converting a string to a date in JavaScript

The best string format for string parsing is the date ISO format together with the JavaScript Date object constructor.

Examples of ISO format: YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS.

But wait! Just using the "ISO format" doesn't work reliably by itself. String are sometimes parsed as UTC and sometimes as localtime (based on browser vendor and version). The best practice should always be to store dates as UTC and make computations as UTC.

To parse a date as UTC, append a Z - e.g.: new Date('2011-04-11T10:20:30Z').

To display a date in UTC, use .toUTCString(),
to display a date in user's local time, use .toString().

More info on MDN | Date and this answer.

For old Internet Explorer compatibility (IE versions less than 9 do not support ISO format in Date constructor), you should split datetime string representation to it's parts and then you can use constructor using datetime parts, e.g.: new Date('2011', '04' - 1, '11', '11', '51', '00'). Note that the number of the month must be 1 less.

Alternate method - use an appropriate library:

You can also take advantage of the library Moment.js that allows parsing date with the specified time zone.

ReadFile in Base64 Nodejs

I think that the following example demonstrates what you need:

The essence of the article is this code part:

var fs = require('fs');

// function to encode file data to base64 encoded string
function base64_encode(file) {
    // read binary data
    var bitmap = fs.readFileSync(file);
    // convert binary data to base64 encoded string
    return new Buffer(bitmap).toString('base64');

// function to create file from base64 encoded string
function base64_decode(base64str, file) {
    // create buffer object from base64 encoded string, it is important to tell the constructor that the string is base64 encoded
    var bitmap = new Buffer(base64str, 'base64');
    // write buffer to file
    fs.writeFileSync(file, bitmap);
    console.log('******** File created from base64 encoded string ********');

// convert image to base64 encoded string
var base64str = base64_encode('kitten.jpg');
// convert base64 string back to image 
base64_decode(base64str, 'copy.jpg');

JavaScript private methods

Wrap all code in Anonymous Function: Then , all functions will be private ,ONLY functions attached to window object :

         return this;


       return 'My name is ';


Use this :

  var abdennour=new Person('Abdennour');


Twitter bootstrap collapse: change display of toggle button

Some may take issue with changing the Bootstrap js (and perhaps validly so) but here is a two line approach to achieving this.

In bootstrap.js, look for the function and modify the this.$trigger call to add the html change as follows:

  .attr('aria-expanded', true)

Likewise in the Collapse.prototype.hide function change it to

  .attr('aria-expanded', false)

This will toggle the text between "Collapse" when everything is expanded and "Expand" when everything is collapsed.

Two lines. Done.

EDIT: longterm this won't work. bootstrap.js is part of a Nuget package so I don't think it was propogating my change to the server. As mentioned previously, not best practice anyway to edit bootstrap.js, so I implemented PSL's solution which worked great. Nonetheless, my solution will work locally if you need something quick just to try it out.

Eslint: How to disable "unexpected console statement" in Node.js?

In package.json you will find an eslintConfig line. Your 'rules' line can go in there like this:

  "eslintConfig": {
    "extends": [
    "rules": {
      "no-console": "off"

Remove a parameter to the URL with JavaScript

Try this. Just pass in the param you want to remove from the URL and the original URL value, and the function will strip it out for you.

function removeParam(key, sourceURL) {
    var rtn = sourceURL.split("?")[0],
        params_arr = [],
        queryString = (sourceURL.indexOf("?") !== -1) ? sourceURL.split("?")[1] : "";
    if (queryString !== "") {
        params_arr = queryString.split("&");
        for (var i = params_arr.length - 1; i >= 0; i -= 1) {
            param = params_arr[i].split("=")[0];
            if (param === key) {
                params_arr.splice(i, 1);
        if (params_arr.length) rtn = rtn + "?" + params_arr.join("&");
    return rtn;

To use it, simply do something like this:

var originalURL = "";
var alteredURL = removeParam("color_id", originalURL);

The var alteredURL will be the output you desire.

Hope it helps!

Remove property for all objects in array

For my opinion this is the simplest variant{good}) => ({good}))

Redirect form to different URL based on select option element

Just use a onchnage Event for select box.

<select id="selectbox" name="" onchange="javascript:location.href = this.value;">
    <option value="" selected>Option1</option>
    <option value="">Option2</option>
    <option value="">Option3</option>


And if selected option to be loaded at the page load then add some javascript code

<script type="text/javascript">
    window.onload = function(){

for jQuery: Remove the onchange event from <select> tag

jQuery(function () {
    // remove the below comment in case you need chnage on document ready
    // location.href=jQuery("#selectbox").val(); 
    jQuery("#selectbox").change(function () {
        location.href = jQuery(this).val();

How to check for an undefined or null variable in JavaScript?

If you try and reference an undeclared variable, an error will be thrown in all JavaScript implementations.

Properties of objects aren't subject to the same conditions. If an object property hasn't been defined, an error won't be thrown if you try and access it. So in this situation you could shorten:

 if (typeof(myObj.some_property) != "undefined" && myObj.some_property != null)


if (myObj.some_property != null)

With this in mind, and the fact that global variables are accessible as properties of the global object (window in the case of a browser), you can use the following for global variables:

if (window.some_variable != null) {
    // Do something with some_variable

In local scopes, it always useful to make sure variables are declared at the top of your code block, this will save on recurring uses of typeof.

How to create new div dynamically, change it, move it, modify it in every way possible, in JavaScript?

Have you tried JQuery? Vanilla javascript can be tough. Try using this:

$('.container-element').add('<div>Insert Div Content</div>');

.container-element is a JQuery selector that marks the element with the class "container-element" (presumably the parent element in which you want to insert your divs). Then the add() function inserts HTML into the container-element.

How do I remove an object from an array with JavaScript?

I use this quite a bit so I created a small prototype. Simply looks for the item then pulls it out if there is a match.

//Prototype to remove object from array, removes first
//matching object only
Array.prototype.remove = function (v) {
    if (this.indexOf(v) != -1) {
        this.splice(this.indexOf(v), 1);
        return true;
    return false;

Can be called like:

var arr = [12, 34, 56];

The result would be [12, 56]

Has a boolean return if there was a successful remove, false if the element didn't exist.

how to show calendar on text box click in html

HTML Date Picker You can refer this.

How do I check if an element is hidden in jQuery?

You can also:

  // Checks CSS content for display:[none|block], ignores visibility:[true|false]
  if ($("#accordionZiarat").is(":visible")) {

  else if ($("#accordionZiarat").is(":hidden")) {



canvas.toDataURL() SecurityError

This method will prevent you from getting an 'Access-Control-Allow-Origin' error from the server you are accessing to.

var img = new Image();
var timestamp = new Date().getTime();
img.setAttribute('crossOrigin', 'anonymous');
img.src = url + '?' + timestamp;

Simple way to get element by id within a div tag?

In HTML ids should be unique. I suggest you change your code to something like this:

<div id="div1" >
    <input type="text" name="edit1" id="edit1" />
    <input type="text" name="edit2" id="edit2" />
<div id="div2" >
    <input type="text" name="edit1" id="edit3" />
    <input type="text" name="edit2" id="edit4" />

How to embed fonts in HTML?

Check out Typekit, a commercial option (they have a free package available too).

It uses different techniques depending on which browser is being used (@font-face vs. EOT format), and they take care of all the font licensing issues for you also. It supports everything down to IE6.

Here's some more info about how Typekit works:

What does `return` keyword mean inside `forEach` function?

From the Mozilla Developer Network:

There is no way to stop or break a forEach() loop other than by throwing an exception. If you need such behavior, the forEach() method is the wrong tool.

Early termination may be accomplished with:

The other Array methods: every(), some(), find(), and findIndex() test the array elements with a predicate returning a truthy value to determine if further iteration is required.

AngularJS: How to run additional code after AngularJS has rendered a template?

This post is old, but I change your code to:

scope.$watch("assignments", function (value) {//I change here
  var val = value || null;            
  if (val)
    element.dataTable({"bDestroy": true});

see jsfiddle.

I hope it helps you

JavaScript Infinitely Looping slideshow with delays?

The correct approach is to use a single timer. Using setInterval, you can achieve what you want as follows:

window.onload = function start() {
function slide() {
    var num = 0, style = document.getElementById('container').style;
    window.setInterval(function () {
        // increase by num 1, reset to 0 at 4
        num = (num + 1) % 4;

        // -600 * 1 = -600, -600 * 2 = -1200, etc 
        style.marginLeft = (-600 * num) + "px"; 
    }, 3000); // repeat forever, polling every 3 seconds

How to embed an autoplaying YouTube video in an iframe?

Since April 2018, Google made some changes to the Autoplay Policy. You not only need to add the autoplay=1 as a query param, but also add allow='autoplay' as an iframe's attribute

So you will have to do something like this:

<iframe src="" allow='autoplay'></iframe>

jQuery document.createElement equivalent?

Creating new DOM elements is a core feature of the jQuery() method, see:

jQuery function to get all unique elements from an array?

If anyone is using knockoutjs try:


BTW have look at all ko.utils.array* utilities.

javascript: calculate x% of a number

I use two very useful JS functions:

function rangeToPercent(number, min, max){
   return ((number - min) / (max - min));


function percentToRange(percent, min, max) {
   return((max - min) * percent + min);

How to use jQuery to get the current value of a file input field

its not .val() if you want to get file /home/user/default.png it will get with .val() just default.png

Check if an element has event listener on it. No jQuery

Nowadays (2016) in Chrome Dev Tools console, you can quickly execute this function below to show all event listeners that have been attached to an element.


How to save an HTML5 Canvas as an image on a server?

I just made an imageCrop and Upload feature with

to get the ImagePreview ( the cropped image rendering in a canvas)

canvas.toBlob(function(blob){...}, 'image/jpeg', 0.95);

I prefer sending data in blob with content type image/jpeg rather than toDataURL ( a huge base64 string`

My implementation for uploading to Azure Blob using SAS URL, image_in_blob, {
   headers: {
      'x-ms-blob-type': 'BlockBlob',
      'Content-Type': 'image/jpeg'

Disable/Enable Submit Button until all forms have been filled

Put it inside a table and then do on her:

var tabPom = document.getElementById("tabPomId");
$(tabPom ).prop('disabled', true/false);

Escaping HTML strings with jQuery

function htmlDecode(t){
   if (t) return $('<div />').html(t).text();

works like a charm

JavaScript Array to Set

Just pass the array to the Set constructor. The Set constructor accepts an iterable parameter. The Array object implements the iterable protocol, so its a valid parameter.

var arr = [55, 44, 65];_x000D_
var set = new Set(arr);_x000D_
console.log(set.size === arr.length);_x000D_

See here

jQuery Find and List all LI elements within a UL within a specific DIV


// or:


Now that you added that comment explaining that you want to "form an array of rels per column", you should do this:

var rels = [];

$('ul').each(function() {
    var localRels = [];

        localRels.push( $(this).attr('rel') );


calling Jquery function from javascript

You can't.


    function my_fun(){
           /.. some operations ../

That is a closure. my_fun() is defined only inside of that anonymous function. You can only call my_fun() if you declare it at the correct level of scope, i.e., globally.

$(function () {/* something */}) is an IIFE, meaning it executes immediately when the DOM is ready. By declaring my_fun() inside of that anonymous function, you prevent the rest of the script from "seeing" it.

Of course, if you want to run this function when the DOM has fully loaded, you should do the following:

function my_fun(){
    /* some operations */

    my_fun(); //run my_fun() ondomready

// just js
function js_fun(){
   my_fun(); //== call my_fun() again

how to assign a block of html code to a javascript variable

you can make a javascript object with key being name of the html snippet, and value being an array of html strings, that are joined together.

var html = {
      '<div class="top_crimes"><h3>Top Crimes</h3></div>',
      '<table class="crimes-table table table-responsive table-bordered">',
            '<span class="list-heading">Crime:</span>',
            '<span id="last_crime_span"># Arrests</span>',
      '<div class="top_teams"><h3>Top Teams</h3></div>',
      '<table class="teams-table table table-responsive table-bordered">',
            '<span class="list-heading">Team:</span>',
            '<span id="last_team_span"># Arrests</span>',
      '<div class="top_players"><h3>Top Players</h3></div>',
      '<table class="players-table table table-responsive table-bordered">',
            '<span class="list-heading">Players:</span>',
            '<span id="last_player_span"># Arrests</span>',
}; with target "_blank" in Chrome

"_blank" is not guaranteed to be a new tab or window. It's implemented differently per-browser.

You can, however, put anything into target. I usually just say "_tab", and every browser I know of just opens it in a new tab.

Be aware that it means it's a named target, so if you try to open 2 URLs, they will use the same tab.

How to check if object has any properties in JavaScript?

ES6 function

 * Returns true if an object is empty.
 * @param  {*} obj the object to test
 * @return {boolean} returns true if object is empty, otherwise returns false
const pureObjectIsEmpty = obj => obj && obj.constructor === Object && Object.keys(obj).length === 0


let obj = "this is an object with String constructor"
console.log(pureObjectIsEmpty(obj)) // empty? true

obj = {}
console.log(pureObjectIsEmpty(obj)) // empty? true

obj = []
console.log(pureObjectIsEmpty(obj)) // empty? true

obj = [{prop:"value"}]
console.log(pureObjectIsEmpty(obj)) // empty? true

obj = {prop:"value"}
console.log(pureObjectIsEmpty(obj)) // empty? false

Selecting multiple classes with jQuery

Have you tried this?

$('.myClass, .myOtherClass').removeClass('theclass');

How do I uniquely identify computers visiting my web site?

The suggestions to use cookies aside, the only comprehensive set of identifying attributes available to interrogate are contained in the HTTP request header. So it is possible to use some subset of these to create a pseudo-unique identifier for a user agent (i.e., browser). Further, most of this information is possibly already being logged in the so-called "access log" of your web server software by default and, if not, can be easily configured to do so. Then, a utlity could be developed that simply scans the content of this log, creating fingerprints of each request comprised of, say, the IP address and User Agent string, etc. The more data available, even including the contents of specific cookies, adds to the quality of the uniqueness of this fingerprint. Though, as many others have stated already, the HTTP protocol doesn't make this 100% foolproof - at best it can only be a fairly good indicator.

Can I pass parameters in computed properties in Vue.Js

Most probably you want to use a method

<span>{{ fullName('Hi') }}</span>

methods: {
  fullName(salut) {
      return `${salut} ${this.firstName} ${this.lastName}`

Longer explanation

Technically you can use a computed property with a parameter like this:

computed: {
   fullName() {
      return salut => `${salut} ${this.firstName} ${this.lastName}`

(Thanks Unirgy for the base code for this.)

The difference between a computed property and a method is that computed properties are cached and change only when their dependencies change. A method will evaluate every time it's called.

If you need parameters, there are usually no benefits of using a computed property function over a method in such a case. Though it allows you to have a parametrized getter function bound to the Vue instance, you lose caching so not really any gain there, in fact, you may break reactivity (AFAIU). You can read more about this in Vue documentation

The only useful situation is when you have to use a getter and need to have it parametrized. For instance, this situation happens in Vuex. In Vuex it's the only way to synchronously get parametrized result from the store (actions are async). Thus this approach is listed by official Vuex documentation for its getters

How do I convert a C# List<string[]> to a Javascript array?

For those trying to do it without using JSON, the following is how I did it:

    var originalLabels = [ '@Html.Raw(string.Join("', '", Model.labels))'];

Adding a new array element to a JSON object

JSON is just a notation; to make the change you want parse it so you can apply the changes to a native JavaScript Object, then stringify back to JSON

var jsonStr = '{"theTeam":[{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"3","status":"member"}]}';

var obj = JSON.parse(jsonStr);
jsonStr = JSON.stringify(obj);
// "{"theTeam":[{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"3","status":"member"},{"teamId":"4","status":"pending"}]}"

How to check a not-defined variable in JavaScript

The void operator returns undefined for any argument/expression passed to it. so you can test against the result (actually some minifiers change your code from undefined to void 0 to save a couple of characters)

For example:

void 0
// undefined

if (variable === void 0) {
    // variable is undefined

Load local javascript file in chrome for testing?

The easiest workaround I have found is to use Firefox. Not only does it work with no extra steps (drag and drop - no muss no fuss), but blackboxing works better than Chrome.

Bootstrap 4 File Input

Bootstrap 4

More details are here

Today I need to create a browse button with multi-upload files option all above snippets are not good for me.

The official Bootstrap example is also not working when I select multiple files.

I come up with this code may be will help others in the future.

<div class="container mt-5">
  <h1 class="text-center">Bootstrap 4 Upload multiple files</h1>
  <div class="col-sm-4 mr-auto ml-auto border p-4">
  <form method="post" enctype="multipart/form-data" action="upload.php">
    <div class="form-group">
      <label><strong>Upload Files</strong></label>
      <div class="custom-file">
        <input type="file" name="files[]" multiple class="custom-file-input form-control" id="customFile">
        <label class="custom-file-label" for="customFile">Choose file</label>
    <div class="form-group">
      <button type="submit" name="upload" value="upload" id="upload" class="btn btn-block btn-dark"><i class="fa fa-fw fa-upload"></i> Upload</button>

The js code is given below.

$(document).ready(function() {
  $('input[type="file"]').on("change", function() {
    let filenames = [];
    let files = document.getElementById("customFile").files;
    if (files.length > 1) {
      filenames.push("Total Files (" + files.length + ")");
    } else {
      for (let i in files) {
        if (files.hasOwnProperty(i)) {

The working code example is given here with bootstrap 3 and bootstrap 4.3.1.

jQuery - Create hidden form element on the fly


To answer your second question:

    type: 'hidden',
    id: 'foo',
    name: 'bar'

How to convert a full date to a short date in javascript?

Try this:

new Date().toLocaleFormat("%x");

How to include Javascript file in Asp.Net page

If your page is deeply pathed or might move around and your JS script is at "~/JS/Registration.js" of your web folder, you can try the following:

<script src='<%=ResolveClientUrl("~/JS/Registration.js") %>' 

How do I URl encode something in Node.js?

Use the escape function of querystring. It generates a URL safe string.

var escaped_str = require('querystring').escape('Photo on 30-11-12 at 8.09 AM #2.jpg');
// prints 'Photo%20on%2030-11-12%20at%208.09%20AM%20%232.jpg'

JavaScript: Get image dimensions

var img = new Image();

img.onload = function(){
  var height = img.height;
  var width = img.width;

  // code here to use the dimensions

img.src = url;

$.ajax( type: "POST" POST method to php

Check whether title has any value or not. If not, then retrive the value using Id.

Title : <input type="text" id="title" size="40" name="title" value = ''/>
<input type="button" onclick="headingSearch(this.form)" value="Submit"/><br /><br />
<script type="text/javascript">
function headingSearch(f)
    var title=jQuery('#title').val();
      type: "POST",
      url: "edit.php",
      data: {title:title} ,
      success: function(data) {

Try this code.

In php code, use echo instead of return. Only then, javascript data will have its value.

Bootstrap: Open Another Modal in Modal

$(document).on('', function (event) {_x000D_
  if ($('.modal:visible').length) {_x000D_

How to loop through a plain JavaScript object with the objects as members?

I think it's worth pointing out that jQuery sorts this out nicely with $.each().

See: .each()


$('.foo').each(function() {

$(this) being the single item inside the object. Swap $('.foo') to a variable if you don't want to use jQuery's selector engine.

Detect when a window is resized using JavaScript ?

Another way of doing this, using only JavaScript, would be this:

window.addEventListener('resize', functionName);

This fires every time the size changes, like the other answer.

functionName is the name of the function being executed when the window is resized (the brackets on the end aren't necessary).

What does [object Object] mean? (JavaScript)

Alerts aren't the best for displaying objects. Try console.log? If you still see Object Object in the console, use JSON.parse like this > var obj = JSON.parse(yourObject); console.log(obj)

Change div height on button click

var ww1 = "";_x000D_
var ww2 = 0;_x000D_
var myVar1 ;_x000D_
var myVar2 ;_x000D_
function wm1(){_x000D_
  myVar1 =setInterval(w1, 15);_x000D_
function wm2(){_x000D_
  myVar2 =setInterval(w2, 15);_x000D_
function w1(){_x000D_
 ww2= ww1.replace("px", ""); _x000D_
    if(parseFloat(ww2) <= 200){_x000D_
document.getElementById('chartdiv').style.height = (parseFloat(ww2)+5) + 'px';_x000D_
function w2(){_x000D_
 ww2= ww1.replace("px", ""); _x000D_
    if(parseFloat(ww2) >= 50){_x000D_
document.getElementById('chartdiv').style.height = (parseFloat(ww2)-5) + 'px';_x000D_
  <head>    _x000D_
<body >_x000D_
    <button type="button" onClick = "wm1()">200px</button>_x000D_
    <button type="button" onClick = "wm2()">50px</button>_x000D_
    <div id="chartdiv" style="width: 100%; height: 50px; background-color:#ccc"></div>_x000D_
  <div id="demo"></div>_x000D_

How to use ES6 Fat Arrow to .filter() an array of objects

As simple as you can use const adults = family.filter(({ age }) => age > 18 );

const family =[{"name":"Jack",  "age": 26},_x000D_
              {"name":"Jill",  "age": 22},_x000D_
              {"name":"James", "age": 5 },_x000D_
              {"name":"Jenny", "age": 2 }];_x000D_
const adults = family.filter(({ age }) => age > 18 );_x000D_

forEach is not a function error with JavaScript array

You can check if you typed forEach correctly, if you typed foreach like in other programming languages it won't work.

How do I remove documents using Node.js Mongoose?

docs is an array of documents. so it doesn't have a mongooseModel.remove() method.

You can iterate and remove each document in the array separately.

Or - since it looks like you are finding the documents by a (probably) unique id - use findOne instead of find.

HTML5 Canvas vs. SVG vs. div

While there is still some truth to most of the answers above, I think they deserve an update:

Over the years the performance of SVG has improved a lot and now there is hardware-accelerated CSS transitions and animations for SVG that do not depend on JavaScript performance at all. Of course JavaScript performance has improved, too and with it the performance of Canvas, but not as much as SVG got improved. Also there is a "new kid" on the block that is available in almost all browsers today and that is WebGL. To use the same words that Simon used above: It beats both Canvas and SVG hands down. This doesn't mean it should be the go-to technology, though, since it's a beast to work with and it is only faster in very specific use-cases.

IMHO for most use-cases today, SVG gives the best performance/usability ratio. Visualizations need to be really complex (with respect to number of elements) and really simple at the same time (per element) so that Canvas and even more so WebGL really shine.

In this answer to a similar question I am providing more details, why I think that the combination of all three technologies sometimes is the best option you have.

JavaScript variable number of arguments to function

It is preferable to use rest parameter syntax as Ramast pointed out.

function (a, b, ...args) {}

I just want to add some nice property of the ...args argument

  1. It is an array, and not an object like arguments. This allows you to apply functions like map or sort directly.
  2. It does not include all parameters but only the one passed from it on. E.g. function (a, b, ...args) in this case args contains argument 3 to arguments.length

How to differentiate single click event and double click event?

You need to use a timeout to check if there is an another click after the first click.

Here is the trick:

// Author:  Jacek Becela
// Source:
// License: MIT

jQuery.fn.single_double_click = function(single_click_callback, double_click_callback, timeout) {
  return this.each(function(){
    var clicks = 0, self = this;
      if (clicks == 1) {
          if(clicks == 1) {
  , event);
          } else {
  , event);
          clicks = 0;
        }, timeout || 300);


$("button").single_double_click(function () {
  alert("Try double-clicking me!")
}, function () {
  alert("Double click detected, I'm hiding")
<button>Click Me!</button>


As stated below, prefer using the native dblclick event:

Or the one provided by jQuery:

How to get datetime in JavaScript?

function pad_2(number)
     return (number < 10 ? '0' : '') + number;

function hours(date)
    var hours = date.getHours();
    if(hours > 12)
        return hours - 12; // Substract 12 hours when 13:00 and more
    return hours;

function am_pm(date)
    if(date.getHours()==0 && date.getMinutes()==0 && date.getSeconds()==0)
        return ''; // No AM for MidNight
    if(date.getHours()==12 && date.getMinutes()==0 && date.getSeconds()==0)
        return ''; // No PM for Noon
        return ' AM';
    return ' PM';

function date_format(date)
     return pad_2(date.getDate()) + '/' +
            pad_2(date.getMonth()+1) + '/' +
            (date.getFullYear() + ' ').substring(2) +
            pad_2(hours(date)) + ':' +
            pad_2(date.getMinutes()) +

Code corrected as of Sep 3 '12 at 10:11 as modal popup?

You can try open a modal dialog with html5 and css3, try this code:

.windowModal {_x000D_
    position: fixed;_x000D_
    font-family: Arial, Helvetica, sans-serif;_x000D_
    top: 0;_x000D_
    right: 0;_x000D_
    bottom: 0;_x000D_
    left: 0;_x000D_
    background: rgba(0,0,0,0.8);_x000D_
    z-index: 99999;_x000D_
    -webkit-transition: opacity 400ms ease-in;_x000D_
    -moz-transition: opacity 400ms ease-in;_x000D_
    transition: opacity 400ms ease-in;_x000D_
    pointer-events: none;_x000D_
.windowModal:target {_x000D_
    pointer-events: auto;_x000D_
.windowModal > div {_x000D_
    width: 400px;_x000D_
    position: relative;_x000D_
    margin: 10% auto;_x000D_
    padding: 5px 20px 13px 20px;_x000D_
    border-radius: 10px;_x000D_
    background: #fff;_x000D_
    background: -moz-linear-gradient(#fff, #999);_x000D_
    background: -webkit-linear-gradient(#fff, #999);_x000D_
    background: -o-linear-gradient(#fff, #999);_x000D_
.close {_x000D_
    background: #606061;_x000D_
    color: #FFFFFF;_x000D_
    line-height: 25px;_x000D_
    position: absolute;_x000D_
    right: -12px;_x000D_
    text-align: center;_x000D_
    top: -10px;_x000D_
    width: 24px;_x000D_
    text-decoration: none;_x000D_
    font-weight: bold;_x000D_
    -webkit-border-radius: 12px;_x000D_
    -moz-border-radius: 12px;_x000D_
    border-radius: 12px;_x000D_
    -moz-box-shadow: 1px 1px 3px #000;_x000D_
    -webkit-box-shadow: 1px 1px 3px #000;_x000D_
    box-shadow: 1px 1px 3px #000;_x000D_
.close:hover { background: #00d9ff; }
<a href="#divModal">Open Modal Window</a>_x000D_
<div id="divModal" class="windowModal">_x000D_
        <a href="#close" title="Close" class="close">X</a>_x000D_
        <h2>Modal Dialog</h2>_x000D_
        <p>This example shows a modal window without using javascript only using html5 and css3, I try it it¡</p>_x000D_
        <p>Using javascript, with new versions of html5 and css3 is not necessary can do whatever we want without using js libraries.</p>_x000D_

Pass C# ASP.NET array to Javascript array

This is to supplement zerkms's answer.

To pass data across language barriers, you would need a way to represent the data as a string by serializing the data. One of the serialization methods for JavaScript is JSON. In zerkms's example, the code would be placed inside of an aspx page. To combine his example and yours together on one aspx page, you would have,

    int[] numbers = new int[5];
    // Fill up numbers...

    var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();

somewhere later on the aspx page

<script type="text/javascript">
    var jsVariable = <%= serializer.Serialize(numbers) %>;

This answer though, assumes that you are generating JavaScript from the initial page load. As per the comments in your post, this could have been done via AJAX. In that case, you would have the server respond with the result of the serialization and then deserialize it in JavaScript using your favorite framework.

Note: Also do not mark this as an answer since I wanted the syntax highlighting to make another answer more clear.

How to show full object in Chrome console?

I made a function of the Trident D'Gao answer.

function print(obj) {
  console.log(JSON.stringify(obj, null, 4));

How to use it


Submitting a form on 'Enter' with jQuery?

I use now


At first I added an eventhandler to the submit button which produced an error for me.

Array vs. Object efficiency in JavaScript

I had a similar problem that I am facing where I need to store live candlesticks from an event source limited to x items. I could have them stored in an object where the timestamp of each candle would act as the key and the candle itself would act as the value. Another possibility was that I could store it in an array where each item was the candle itself. One problem about live candles is that they keep sending updates on the same timestamp where the latest update holds the most recent data therefore you either update an existing item or add a new one. So here is a nice benchmark that attempts to combine all 3 possibilities. Arrays in the solution below are atleast 4x faster on average. Feel free to play

"use strict";

const EventEmitter = require("events");
let candleEmitter = new EventEmitter();

//Change this to set how fast the setInterval should run
const frequency = 1;

setInterval(() => {
    // Take the current timestamp and round it down to the nearest second
    let time = Math.floor( / 1000) * 1000;
    let open = Math.random();
    let high = Math.random();
    let low = Math.random();
    let close = Math.random();
    let baseVolume = Math.random();
    let quoteVolume = Math.random();

    //Clear the console everytime before printing fresh values

    candleEmitter.emit("candle", {
        symbol: "ABC:DEF",
        time: time,
        open: open,
        high: high,
        low: low,
        close: close,
        baseVolume: baseVolume,
        quoteVolume: quoteVolume

}, frequency)

// Test 1 would involve storing the candle in an object
candleEmitter.on('candle', storeAsObject)

// Test 2 would involve storing the candle in an array
candleEmitter.on('candle', storeAsArray)

//Container for the object version of candles
let objectOhlc = {}

//Container for the array version of candles
let arrayOhlc = {}

//Store a max 30 candles and delete older ones
let limit = 30

function storeAsObject(candle) {

    //measure the start time in nanoseconds
    const hrtime1 = process.hrtime()
    const start = hrtime1[0] * 1e9 + hrtime1[1]

    const { symbol, time } = candle;

    // Create the object structure to store the current symbol
    if (typeof objectOhlc[symbol] === 'undefined') objectOhlc[symbol] = {}

    // The timestamp of the latest candle is used as key with the pair to store this symbol
    objectOhlc[symbol][time] = candle;

    // Remove entries if we exceed the limit
    const keys = Object.keys(objectOhlc[symbol]);
    if (keys.length > limit) {
        for (let i = 0; i < (keys.length - limit); i++) {
            delete objectOhlc[symbol][keys[i]];

    //measure the end time in nano seocnds
    const hrtime2 = process.hrtime()
    const end = hrtime2[0] * 1e9 + hrtime2[1]

    console.log("Storing as objects", end - start, Object.keys(objectOhlc[symbol]).length)

function storeAsArray(candle) {

    //measure the start time in nanoseconds
    const hrtime1 = process.hrtime()
    const start = hrtime1[0] * 1e9 + hrtime1[1]

    const { symbol, time } = candle;
    if (typeof arrayOhlc[symbol] === 'undefined') arrayOhlc[symbol] = []

    //Get the bunch of candles currently stored
    const candles = arrayOhlc[symbol];

    //Get the last candle if available
    const lastCandle = candles[candles.length - 1] || {};

    // Add a new entry for the newly arrived candle if it has a different timestamp from the latest one we storeds
    if (time !== lastCandle.time) {

    //If our newly arrived candle has the same timestamp as the last stored candle, update the last stored candle
    else {
        candles[candles.length - 1] = candle

    if (candles.length > limit) {
        candles.splice(0, candles.length - limit);

    //measure the end time in nano seocnds
    const hrtime2 = process.hrtime()
    const end = hrtime2[0] * 1e9 + hrtime2[1]

    console.log("Storing as array", end - start, arrayOhlc[symbol].length)

Conclusion 10 is the limit here

Storing as objects 4183 nanoseconds 10
Storing as array 373 nanoseconds 10

Is there a way to create and run javascript in Chrome?

Open a basic text editor and type out your html. Save it as .html If you type in file:///C:/ into the address bar you can then navigate to your chosen file and run it. If you want to open a file that is on a server type in file:/// and instead of C:/ the first letter of the server followed by :/.

Perform curl request in javascript?

curl is a command in linux (and a library in php). Curl typically makes an HTTP request.

What you really want to do is make an HTTP (or XHR) request from javascript.

Using this vocab you'll find a bunch of examples, for starters: Sending authorization headers with jquery and ajax

Essentially you will want to call $.ajax with a few options for the header, etc.

        url: '',
        beforeSend: function(xhr) {
             xhr.setRequestHeader("Authorization", "Bearer 6QXNMEMFHNY4FJ5ELNFMP5KRW52WFXN5")
        }, success: function(data){
            //process the JSON data etc

jQuery click events firing multiple times

To make sure a click only actions once use this:

$(".bet").unbind().click(function() {

How to replace innerHTML of a div using jQuery?


$("#regTitle").html('Hello World');


$ is equivalent to jQuery. Both represent the same object in the jQuery library. The "#regTitle" inside the parenthesis is called the selector which is used by the jQuery library to identify which element(s) of the html DOM (Document Object Model) you want to apply code to. The # before regTitle is telling jQuery that regTitle is the id of an element inside the DOM.

From there, the dot notation is used to call the html function which replaces the inner html with whatever parameter you place in-between the parenthesis, which in this case is 'Hello World'.

<script> tag vs <script type = 'text/javascript'> tag

In HTML 4, the type attribute is required. In my experience, all browsers will default to text/javascript if it is absent, but that behaviour is not defined anywhere. While you can in theory leave it out and assume it will be interpreted as JavaScript, it's invalid HTML, so why not add it.

In HTML 5, the type attribute is optional and defaults to text/javascript

Use <script type="text/javascript"> or simply <script> (if omitted, the type is the same). Do not use <script language="JavaScript">; the language attribute is deprecated

Ref :
Difference between <script> tag with type and <script> without type?

Do you need type attribute at all?

I am using HTML5- No

I am not using HTML5 - Yes

How to get the difference between two arrays in JavaScript?

How about this:

Array.prototype.contains = function(needle){
  for (var i=0; i<this.length; i++)
    if (this[i] == needle) return true;

  return false;

Array.prototype.diff = function(compare) {
    return this.filter(function(elem) {return !compare.contains(elem);})

var a = new Array(1,4,7, 9);
var b = new Array(4, 8, 7);

So this way you can do array1.diff(array2) to get their difference (Horrible time complexity for the algorithm though - O(array1.length x array2.length) I believe)

Check if all values of array are equal

Well, this is really not very complicated. I have strong suspicion you didn't even try. What you do is that you pick the first value, save it in the variable, and then, within a for loop, compare all subsequent values with the first one.
I intentionally didn't share any code. Find how for is used and how variables are compared.

Access a JavaScript variable from PHP

If showing data to the user, do a redirect:

<script language="JavaScript">
    var tester = "foobar";
    document.location="" + tester;

or an iframe:

<script language="JavaScript">
    var tester = "foobar";
    document.write("<iframe src=\"" + tester + "\"></iframe>");

If you don't need user output, create an iframe with width=0 and height=0.

Javascript: best Singleton pattern

Extending the above post by Tom, if you need a class type declaration and access the singleton instance using a variable, the code below might be of help. I like this notation as the code is little self guiding.

function SingletonClass(){
    if ( arguments.callee.instance )
        return arguments.callee.instance;
    arguments.callee.instance = this;

SingletonClass.getInstance = function() {
    var singletonClass = new SingletonClass();
    return singletonClass;

To access the singleton, you would

var singleTon = SingletonClass.getInstance();

How to remove part of a string?

Easiest way I think is:

var s = yourString.replace(/.*_/g,"_");

Inserting a text where cursor is using Javascript/jquery

How to insert some Text to current cursor position of a TextBox through JQuery and JavaScript


  1. Find the Current Cursor Position
  2. Get the Text to be Copied
  3. Set the Text Over there
  4. Update the Cursor position

Here I have 2 TextBoxes and a Button. I have to Click on a certain position on a textbox and then click on the button to paste the text from the other textbox to the the position of the previous textbox.

Main issue here is that getting the current cursor position where we will paste the text.

//Textbox on which to be pasted
<input type="text" id="txtOnWhichToBePasted" />

//Textbox from where to be pasted
<input type="text" id="txtFromWhichToBePasted" />

//Button on which click the text to be pasted
<input type="button" id="btnInsert" value="Insert"/>

<script type="text/javascript">

$(document).ready(function () {
    $('#btnInsert').bind('click', function () {
            var TextToBePasted = $('#txtFromWhichToBePasted').value;
            var ControlOnWhichToBePasted = $('#txtOnWhichToBePasted');

            //Paste the Text
            PasteTag(ControlOnWhichToBePasted, TextToBePasted);

//Function Pasting The Text
function PasteTag(ControlOnWhichToBePasted,TextToBePasted) {
    //Get the position where to be paste

    var CaretPos = 0;
    // IE Support
    if (document.selection) {

        var Sel = document.selection.createRange();

        Sel.moveStart('character', -ctrl.value.length);

        CaretPos = Sel.text.length;
    // Firefox support
    else if (ControlOnWhichToBePasted.selectionStart || ControlOnWhichToBePasted.selectionStart == '0')
        CaretPos = ControlOnWhichToBePasted.selectionStart;

    //paste the text
    var WholeString = ControlOnWhichToBePasted.value;
    var txt1 = WholeString.substring(0, CaretPos);
    var txt2 = WholeString.substring(CaretPos, WholeString.length);
    WholeString = txt1 + TextToBePasted + txt2;
    var CaretPos = txt1.length + TextToBePasted.length;
    ControlOnWhichToBePasted.value = WholeString;

    //update The cursor position 
    setCaretPosition(ControlOnWhichToBePasted, CaretPos);

function setCaretPosition(ControlOnWhichToBePasted, pos) {

    if (ControlOnWhichToBePasted.setSelectionRange) {
        ControlOnWhichToBePasted.setSelectionRange(pos, pos);
    else if (ControlOnWhichToBePasted.createTextRange) {
        var range = ControlOnWhichToBePasted.createTextRange();
        range.moveEnd('character', pos);
        range.moveStart('character', pos);;


How to globally replace a forward slash in a JavaScript string?

You need to wrap the forward slash to avoid cross browser issues or //commenting out.

str = 'this/that and/if';

var newstr = str.replace(/[/]/g, 'ForwardSlash');

jQuery - Redirect with post data

This needs clarification. Is your server handling a POST that you want to redirect somewhere else? Or are you wanting to redirect a regulatr GET request to another page that is expecting a POST?

In either case what you can do is something like this:

var f = $('<form>');
$('<input>').attr('name', '...').attr('value', '...');
//after all fields are added

It's probably a good idea to make a link that says "click here if not automatically redirected" to deal with pop-up blockers.

jQuery .css("margin-top", value) not updating in IE 8 (Standards mode)

The correct format for IE8 is:

  $("#ActionBox").css({ 'margin-top': '10px' });  

with this work.

How to create multidimensional array

you can create array follow the code below:

var arraymultidimensional = []
    arraymultidimensional = [[value1,value2],[value3,value4],[value5,value6]];

[v1][v2] position 0
[v3][v4] position 1
[v5][v6] position 2

For add to array dinamically, use the method below:

//vectorvalue format = "[value,value,...]"
function addToArray(vectorvalue){
  arraymultidimensional[arraymultidimensional.length] = vectorvalue;

Hope this helps. :)

event.preventDefault() vs. return false

I think the best way to do this is to use event.preventDefault() because if some exception is raised in the handler, then the return false statement will be skipped and the behavior will be opposite to what you want.

But if you are sure that the code won't trigger any exceptions, then you can go with any of the method you wish.

If you still want to go with the return false, then you can put your entire handler code in a try catch block like below:

$('a').click(function (e) {
      your code here.........
  return false;

Is there an onSelect event or equivalent for HTML <select>?

The wonderful thing about the select tag (in this scenario) is that it will grab its value from the option tags.


<select onChange="javascript:doSomething(this.value);">
<option value="A">A</option>
<option value="B">B</option>
<option value="Foo">C</option>

Worked decent for me.

Permutations in JavaScript?

Similar in spirit to the Haskell-style solution by @crl, but working with reduce:

function permutations( base ) {
  if (base.length == 0) return [[]]
  return permutations( base.slice(1) ).reduce( function(acc,perm) {
    return acc.concat( function(e,pos) {
      var new_perm = perm.slice()
      return new_perm

What is the difference between & vs @ and = in angularJS

AngularJS – Isolated Scopes – @ vs = vs &

Short examples with explanation are available at below link :

@ – one way binding

In directive:

scope : { nameValue : "@name" }

In view:

<my-widget name="{{nameFromParentScope}}"></my-widget>

= – two way binding

In directive:

scope : { nameValue : "=name" },
link : function(scope) { = "Changing the value here will get reflected in parent scope value";

In view:

<my-widget name="{{nameFromParentScope}}"></my-widget>

& – Function call

In directive :

scope : { nameChange : "&" }
link : function(scope) {

In view:

<my-widget nameChange="onNameChange(newName)"></my-widget>

jQuery .search() to any string

if (str.toLowerCase().indexOf("yes") >= 0)


if (/yes/i.test(str))

How to get the value from the GET parameters?

Or if you don't want to reinvent the URI parsing wheel use URI.js

To get the value of a parameter named foo:

new URI((''+document.location)).search(true).foo

What that does is

  1. Convert document.location to a string (it's an object)
  2. Feed that string to URI.js's URI class construtor
  3. Invoke the search() function to get the search (query) portion of the url
    (passing true tells it to output an object)
  4. Access the foo property on the resulting object to get the value

Here's a fiddle for this....

How to read and write into file using JavaScript?

To create file try

function makefile(){
  var fso;
  var thefile;

    fso = new ActiveXObject("Scripting.FileSystemObject");


Create your directory in the C drive because windows has security against writing from web e.g create folder named "tmp" in C drive.

How do I remove javascript validation from my eclipse project?

I was able to exclude the 1.1.1 in Juno by selecting Add Multiple next to the Exlusion Patterns, which brings up the tree, then drilling down to the jquery-mobile folder and selecting that.

This corrected all the warnings for the library!

jQuery input button click event listener

    //Put your code here

Accessing MVC's model property from Javascript

I know its too late but this solution is working perfect for both .net framework and .net core:


Detect URLs in text with JavaScript

Generic Object Oriented Solution

For people like me that use frameworks like angular that don't allow manipulating DOM directly, I created a function that takes a string and returns an array of url/plainText objects that can be used to create any UI representation that you want.

URL regex

For URL matching I used (slightly adapted) h0mayun regex: /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g

My function also drops punctuation characters from the end of a URL like . and , that I believe more often will be actual punctuation than a legit URL ending (but it could be! This is not rigorous science as other answers explain well) For that I apply the following regex onto matched URLs /^(.+?)([.,?!'"]*)$/.

Typescript code

    export function urlMatcherInText(inputString: string): UrlMatcherResult[] {
        if (! inputString) return [];

        const results: UrlMatcherResult[] = [];

        function addText(text: string) {
            if (! text) return;

            const result = new UrlMatcherResult();
            result.type = 'text';
            result.value = text;

        function addUrl(url: string) {
            if (! url) return;

            const result = new UrlMatcherResult();
            result.type = 'url';
            result.value = url;

        const findUrlRegex = /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g;
        const cleanUrlRegex = /^(.+?)([.,?!'"]*)$/;

        let match: RegExpExecArray;
        let indexOfStartOfString = 0;

        do {
            match = findUrlRegex.exec(inputString);

            if (match) {
                const text = inputString.substr(indexOfStartOfString, match.index - indexOfStartOfString);

                var dirtyUrl = match[0];
                var urlDirtyMatch = cleanUrlRegex.exec(dirtyUrl);

                indexOfStartOfString = match.index + dirtyUrl.length;
        while (match);

        const remainingText = inputString.substr(indexOfStartOfString, inputString.length - indexOfStartOfString);

        return results;

    export class UrlMatcherResult {
        public type: 'url' | 'text'
        public value: string

How to select a value in dropdown javascript?

This may do it


HTML table with fixed headers?

I was looking for a solution for this for a while and found most of the answers are not working or not suitable for my situation, so I wrote a simple solution with jQuery.

This is the solution outline:

  1. Clone the table that needs to have a fixed header, and place the cloned copy on top of the original.
  2. Remove the table body from top table.
  3. Remove the table header from bottom table.
  4. Adjust the column widths. (We keep track of the original column widths)

Below is the code in a runnable demo.

function scrolify(tblAsJQueryObject, height) {_x000D_
  var oTbl = tblAsJQueryObject;_x000D_
  // for very large tables you can remove the four lines below_x000D_
  // and wrap the table with <div> in the mark-up and assign_x000D_
  // height and overflow property  _x000D_
  var oTblDiv = $("<div/>");_x000D_
  oTblDiv.css('height', height);_x000D_
  oTblDiv.css('overflow', 'scroll');_x000D_
  // save original width_x000D_
  oTbl.attr("data-item-original-width", oTbl.width());_x000D_
  oTbl.find('thead tr td').each(function() {_x000D_
    $(this).attr("data-item-original-width", $(this).width());_x000D_
  oTbl.find('tbody tr:eq(0) td').each(function() {_x000D_
    $(this).attr("data-item-original-width", $(this).width());_x000D_
  // clone the original table_x000D_
  var newTbl = oTbl.clone();_x000D_
  // remove table header from original table_x000D_
  oTbl.find('thead tr').remove();_x000D_
  // remove table body from new table_x000D_
  newTbl.find('tbody tr').remove();_x000D_
  // replace ORIGINAL COLUMN width    _x000D_
  newTbl.find('thead tr td').each(function() {_x000D_
  oTbl.find('tbody tr:eq(0) td').each(function() {_x000D_
$(document).ready(function() {_x000D_
  scrolify($('#tblNeedsScrolling'), 160); // 160 is height_x000D_
<script src=""></script>_x000D_
<div style="width:300px;border:6px green solid;">_x000D_
  <table border="1" width="100%" id="tblNeedsScrolling">_x000D_
      <tr><th>Header 1</th><th>Header 2</th></tr>_x000D_
      <tr><td>row 1, cell 1</td><td>row 1, cell 2</td></tr>_x000D_
      <tr><td>row 2, cell 1</td><td>row 2, cell 2</td></tr>_x000D_
      <tr><td>row 3, cell 1</td><td>row 3, cell 2</td></tr>_x000D_
      <tr><td>row 4, cell 1</td><td>row 4, cell 2</td></tr>   _x000D_
      <tr><td>row 5, cell 1</td><td>row 5, cell 2</td></tr>_x000D_
      <tr><td>row 6, cell 1</td><td>row 6, cell 2</td></tr>_x000D_
      <tr><td>row 7, cell 1</td><td>row 7, cell 2</td></tr>_x000D_
      <tr><td>row 8, cell 1</td><td>row 8, cell 2</td></tr>   _x000D_

This solution works in Chrome and IE. Since it is based on jQuery, this should work in other jQuery supported browsers as well.

In Angular, how to pass JSON object/array into directive?

If you want to follow all the "best practices," there's a few things I'd recommend, some of which are touched on in other answers and comments to this question.

First, while it doesn't have too much of an affect on the specific question you asked, you did mention efficiency, and the best way to handle shared data in your application is to factor it out into a service.

I would personally recommend embracing AngularJS's promise system, which will make your asynchronous services more composable compared to raw callbacks. Luckily, Angular's $http service already uses them under the hood. Here's a service that will return a promise that resolves to the data from the JSON file; calling the service more than once will not cause a second HTTP request.

app.factory('locations', function($http) {
  var promise = null;

  return function() {
    if (promise) {
      // If we've already asked for this data once,
      // return the promise that already exists.
      return promise;
    } else {
      promise = $http.get('locations/locations.json');
      return promise;

As far as getting the data into your directive, it's important to remember that directives are designed to abstract generic DOM manipulation; you should not inject them with application-specific services. In this case, it would be tempting to simply inject the locations service into the directive, but this couples the directive to that service.

A brief aside on code modularity: a directive’s functions should almost never be responsible for getting or formatting their own data. There’s nothing to stop you from using the $http service from within a directive, but this is almost always the wrong thing to do. Writing a controller to use $http is the right way to do it. A directive already touches a DOM element, which is a very complex object and is difficult to stub out for testing. Adding network I/O to the mix makes your code that much more difficult to understand and that much more difficult to test. In addition, network I/O locks in the way that your directive will get its data – maybe in some other place you’ll want to have this directive receive data from a socket or take in preloaded data. Your directive should either take data in as an attribute through scope.$eval and/or have a controller to handle acquiring and storing the data.

- The 80/20 Guide to Writing AngularJS Directives

In this specific case, you should place the appropriate data on your controller's scope and share it with the directive via an attribute.

app.controller('SomeController', function($scope, locations) {
  locations().success(function(data) {
    $scope.locations = data;
<ul class="list">
   <li ng-repeat="location in locations">
      <a href="#">{{}}. {{}}</a>
<map locations='locations'></map>
app.directive('map', function() {
  return {
    restrict: 'E',
    replace: true,
    template: '<div></div>',
    scope: {
      // creates a scope variable in your directive
      // called `locations` bound to whatever was passed
      // in via the `locations` attribute in the DOM
      locations: '=locations'
    link: function(scope, element, attrs) {
      scope.$watch('locations', function(locations) {
        angular.forEach(locations, function(location, key) {
          // do something

In this way, the map directive can be used with any set of location data--the directive is not hard-coded to use a specific set of data, and simply linking the directive by including it in the DOM will not fire off random HTTP requests.

How to prevent caching of my Javascript file?

Configure your webserver to send caching control HTTP headers for the script.

Fake headers in the HTML documents:

  1. Aren't as well supported as real HTTP headers
  2. Apply to the HTML document, not to resources that it links to

Append an array to another array in JavaScript

If you want to modify the original array instead of returning a new array, use .push()...

array1.push.apply(array1, array2);
array1.push.apply(array1, array3);

I used .apply to push the individual members of arrays 2 and 3 at once.


array1.push.apply(array1, array2.concat(array3));

To deal with large arrays, you can do this in batches.

for (var n = 0, to_add = array2.concat(array3); n < to_add.length; n+=300) {
    array1.push.apply(array1, to_add.slice(n, n+300));

If you do this a lot, create a method or function to handle it.

var push_apply = Function.apply.bind([].push);
var slice_call =[].slice);

Object.defineProperty(Array.prototype, "pushArrayMembers", {
    value: function() {
        for (var i = 0; i < arguments.length; i++) {
            var to_add = arguments[i];
            for (var n = 0; n < to_add.length; n+=300) {
                push_apply(this, slice_call(to_add, n, n+300));

and use it like this:

array1.pushArrayMembers(array2, array3);

var push_apply = Function.apply.bind([].push);_x000D_
var slice_call =[].slice);_x000D_
Object.defineProperty(Array.prototype, "pushArrayMembers", {_x000D_
    value: function() {_x000D_
        for (var i = 0; i < arguments.length; i++) {_x000D_
            var to_add = arguments[i];_x000D_
            for (var n = 0; n < to_add.length; n+=300) {_x000D_
                push_apply(this, slice_call(to_add, n, n+300));_x000D_
var array1 = ['a','b','c'];_x000D_
var array2 = ['d','e','f'];_x000D_
var array3 = ['g','h','i'];_x000D_
array1.pushArrayMembers(array2, array3);_x000D_
document.body.textContent = JSON.stringify(array1, null, 4);

Create table with jQuery - append

Or static HTML without the loop for creating some links (or whatever). Place the <div id="menu"> on any page to reproduce the HTML.

    <!DOCTYPE html>
    <html xmlns="">
        <title>HTML Masterpage</title>
        <script src="//"></script>

        <script type="text/javascript">
            function nav() {
                var menuHTML= '<ul><li><a href="#">link 1</a></li></ul><ul><li><a href="#">link 2</a></li></ul>';

        <style type="text/css">
    <body onload="nav()">
        <div id="menu"></div>

nodejs vs node on ubuntu 12.04

Best way to install nodejs is through NVM (Node Version Manager)

Delete previous versions :

$ sudo apt-get purge node
$ sudo apt autoremove

Also delete all node_modules by $ sudo rm -rf node_modules in the directory containing this folder.

Node & Nodejs are technically the same thing. Just the naming changed.

First Install or update nvm

to run as root

$ sudo su 


$ curl -o- | bash


$ wget -qO- | bash

Check nvm to path

$ source ~/.profile
$ nvm ls-remote

if you get error regarding the listing then install git.

$ sudo apt-get install git

Re-run :

$ nvm ls-remote
$ sudo nvm ls-remote

$ nvm install version-you-require 

Checking Version

# node --version
nvm use version-you-require


How do you remove an array element in a foreach loop?

There are already answers which are giving light on how to unset. Rather than repeating code in all your classes make function like below and use it in code whenever required. In business logic, sometimes you don't want to expose some properties. Please see below one liner call to remove

public static function removeKeysFromAssociativeArray($associativeArray, $keysToUnset)
    if (empty($associativeArray) || empty($keysToUnset))
        return array();

    foreach ($associativeArray as $key => $arr) {
        if (!is_array($arr)) {

        foreach ($keysToUnset as $keyToUnset) {
            if (array_key_exists($keyToUnset, $arr)) {
        $associativeArray[$key] = $arr;
    return $associativeArray;

Call like:

removeKeysFromAssociativeArray($arrValues, $keysToRemove);

Send an Array with an HTTP Get

That depends on what the target server accepts. There is no definitive standard for this. See also a.o. Wikipedia: Query string:

While there is no definitive standard, most web frameworks allow multiple values to be associated with a single field (e.g. field1=value1&field1=value2&field2=value3).[4][5]

Generally, when the target server uses a strong typed programming language like Java (Servlet), then you can just send them as multiple parameters with the same name. The API usually offers a dedicated method to obtain multiple parameter values as an array.

String[] foo = request.getParameterValues("foo"); // [value1, value2, value3]

The request.getParameter("foo") will also work on it, but it'll return only the first value.

String foo = request.getParameter("foo"); // value1

And, when the target server uses a weak typed language like PHP or RoR, then you need to suffix the parameter name with braces [] in order to trigger the language to return an array of values instead of a single value.

$foo = $_GET["foo"]; // [value1, value2, value3]
echo is_array($foo); // true

In case you still use foo=value1&foo=value2&foo=value3, then it'll return only the first value.

$foo = $_GET["foo"]; // value1
echo is_array($foo); // false

Do note that when you send foo[]=value1&foo[]=value2&foo[]=value3 to a Java Servlet, then you can still obtain them, but you'd need to use the exact parameter name including the braces.

String[] foo = request.getParameterValues("foo[]"); // [value1, value2, value3]

Sorting a vector of custom objects

typedef struct Freqamp{
    double freq;
    double amp;

bool struct_cmp_by_freq(FREQAMP a, FREQAMP b)
    return a.freq < b.freq;

    vector <FREQAMP> temp;
    FREQAMP freqAMP;

    freqAMP.freq = 330;
    freqAMP.amp = 117.56;

    freqAMP.freq = 450;
    freqAMP.amp = 99.56;

    freqAMP.freq = 110;
    freqAMP.amp = 106.56;

    sort(temp.begin(),temp.end(), struct_cmp_by_freq);

if compare is false, it will do "swap".

How does inline Javascript (in HTML) work?

using javascript:

here input element is used

<input type="text" id="fname" onkeyup="javascript:console.log(window.event.key)">

if you want to use multiline code use curly braces after javascript:

<input type="text" id="fname" onkeyup="javascript:{ console.log(window.event.key); alert('hello'); }">

How to push local changes to a remote git repository on bitbucket

Meaning the 2nd parameter('master') of the "git push" command -

$ git push origin master

can be made clear by initiating "push" command from 'news-item' branch. It caused local "master" branch to be pushed to the remote 'master' branch. For more information refer

where <refspec> in

[<repository> [<refspec>…?]

is written to mean "specify what destination ref to update with what source object."

For your reference, here is a screen capture how I verified this statement.

<code>enter image description here</code>

How to fill color in a cell in VBA?

You need to use cell.Text = "#N/A" instead of cell.Value = "#N/A". The error in the cell is actually just text stored in the cell.

Git push rejected "non-fast-forward"

Write lock on shared local repository

I had this problem and none of above advises helped me. I was able to fetch everything correctly. But push always failed. It was a local repository located on windows directory with several clients working with it through VMWare shared folder driver. It appeared that one of the systems locked Git repository for writing. After stopping relevant VMWare system, which caused the lock everything repaired immediately. It was almost impossible to figure out, which system causes the error, so I had to stop them one by one until succeeded.

Remove Blank option from Select Option with AngularJS

Here is an updated fiddle:

You needed to set your initial model value to the actual object:

$scope.feed.config = $scope.configs[0];

And update your select to look like this:

<select ng-model="feed.config" ng-options=" for item in configs">

Getting HTTP code in PHP using curl

Try PHP's "get_headers" function.

Something along the lines of:

    $url = '';
    print_r(get_headers($url, 1));

How do I rename a file using VBScript?

I see only one reason your code to not work, missed quote after file name string:


FSO.GetFile("MyFile.txt[missed_quote_here]).Name = "Hello.txt"

PHP - check if variable is undefined

You can use -

Ternary oprator to check wheather value set by POST/GET or not somthing like this

$value1 = $_POST['value1'] = isset($_POST['value1']) ? $_POST['value1'] : '';
$value2 = $_POST['value2'] = isset($_POST['value2']) ? $_POST['value2'] : '';
$value3 = $_POST['value3'] = isset($_POST['value3']) ? $_POST['value3'] : '';
$value4 = $_POST['value4'] = isset($_POST['value4']) ? $_POST['value4'] : '';

Proxies with Python 'Requests' module

i just made a proxy graber and also can connect with same grabed proxy without any input here is :

#Import Modules

from termcolor import colored
from selenium import webdriver
import requests
import os
import sys
import time

#Proxy Grab

options = webdriver.ChromeOptions()
driver = webdriver.Chrome(chrome_options=options)
tbody = driver.find_element_by_tag_name("tbody")
cell = tbody.find_elements_by_tag_name("tr")
for column in cell:

        column = column.text.split(" ")


#Proxy Connection

print(colored('Getting Proxies from graber...','green'))
proxy = {"http": "http://"+ column[0]+":"+column[1]}
url = ''
r = requests.get(url,  proxies=proxy)
print(colored('Connecting using proxy' ,'green'))
sts = r.status_code

How do I keep the screen on in my App?

You can simply use setKeepScreenOn() from the View class.

String concatenation with Groovy

def my_string = "some string"
println "here: " + my_string 

Not quite sure why the answer above needs to go into benchmarks, string buffers, tests, etc.

How to run docker-compose up -d at system start up?

As an addition to user39544's answer, one more type of syntax for crontab -e:

@reboot sleep 60 && /usr/local/bin/docker-compose -f /path_to_your_project/docker-compose.yml up -d

Resize UIImage and change the size of UIImageView

I think what you want is a different content mode. Try using UIViewContentModeScaleToFill. This will scale the content to fit the size of ur UIImageView by changing the aspect ratio of the content if necessary.

Have a look to the content mode section on the official doc to get a better idea of the different content mode available (it is illustrated with images).

How to set JFrame to appear centered, regardless of monitor resolution?

i am using NetBeans IDE 7.2.1 as my developer environmental and there you have an option to configure the JForm properties.

in the JForm Properties go to the 'Code' tab and configure the 'Generate Center'. you will need first to set the Form Size Policy to 'Generate Resize Code'.

Python Request Post with param data

params is for GET-style URL parameters, data is for POST-style body information. It is perfectly legal to provide both types of information in a request, and your request does so too, but you encoded the URL parameters into the URL already.

Your raw post contains JSON data though. requests can handle JSON encoding for you, and it'll set the correct Content-Type header too; all you need to do is pass in the Python object to be encoded as JSON into the json keyword argument.

You could split out the URL parameters as well:

params = {'sessionKey': '9ebbd0b25760557393a43064a92bae539d962103', 'format': 'xml', 'platformId': 1}

then post your data with:

import requests

url = ''

data = {"eventType": "AAS_PORTAL_START", "data": {"uid": "hfe3hf45huf33545", "aid": "1", "vid": "1"}}
params = {'sessionKey': '9ebbd0b25760557393a43064a92bae539d962103', 'format': 'xml', 'platformId': 1}, params=params, json=data)

The json keyword is new in requests version 2.4.2; if you still have to use an older version, encode the JSON manually using the json module and post the encoded result as the data key; you will have to explicitly set the Content-Type header in that case:

import requests
import json

headers = {'content-type': 'application/json'}
url = ''

data = {"eventType": "AAS_PORTAL_START", "data": {"uid": "hfe3hf45huf33545", "aid": "1", "vid": "1"}}
params = {'sessionKey': '9ebbd0b25760557393a43064a92bae539d962103', 'format': 'xml', 'platformId': 1}, params=params, data=json.dumps(data), headers=headers)

Can I use library that used android support with Androidx projects.

Manually adding android.useAndroidX=true and android.enableJetifier=true giving me hard time. Because it's throw some error or Suggestion: add 'tools:replace="android:appComponentFactory"' to <application>

To Enable Jet-fire in project there is option in android Studio

Select Your Project ---> Right Click

app----> Refactor ----> Migrate to AndroidX

Shown in below image:-

enter image description here

After click on Migrate to AndroidX.

It will ask for confirmation and back up for your project.

enter image description here

And last step it will ask you for to do refactor.

enter image description here

After doing Refactor check your have android.useAndroidX=true and android.enableJetifier=true. If they are not then add these two lines to your file:


Note:- Upgrading using Android Studio, this option works if you have android studio 3.2 and onward. Check this

How do I get IntelliJ to recognize common Python modules?

Just create and add Python SDK

File -> Project Structure -> Project -> Project SDK -> new

and select the installation path of your Python interpreter (for example, C:\Python26 in windows and /usr/bin/python2.7 in Linux) as the home path.

Related discussion:

How to create a numpy array of arbitrary length strings?

You can do so by creating an array of dtype=object. If you try to assign a long string to a normal numpy array, it truncates the string:

>>> a = numpy.array(['apples', 'foobar', 'cowboy'])
>>> a[2] = 'bananas'
>>> a
array(['apples', 'foobar', 'banana'], 

But when you use dtype=object, you get an array of python object references. So you can have all the behaviors of python strings:

>>> a = numpy.array(['apples', 'foobar', 'cowboy'], dtype=object)
>>> a
array([apples, foobar, cowboy], dtype=object)
>>> a[2] = 'bananas'
>>> a
array([apples, foobar, bananas], dtype=object)

Indeed, because it's an array of objects, you can assign any kind of python object to the array:

>>> a[2] = {1:2, 3:4}
>>> a
array([apples, foobar, {1: 2, 3: 4}], dtype=object)

However, this undoes a lot of the benefits of using numpy, which is so fast because it works on large contiguous blocks of raw memory. Working with python objects adds a lot of overhead. A simple example:

>>> a = numpy.array(['abba' for _ in range(10000)])
>>> b = numpy.array(['abba' for _ in range(10000)], dtype=object)
>>> %timeit a.copy()
100000 loops, best of 3: 2.51 us per loop
>>> %timeit b.copy()
10000 loops, best of 3: 48.4 us per loop

Detect Close windows event by jQuery

You can use:

$(window).unload(function() {
    //do something

Unload() is deprecated in jQuery version 1.8, so if you use jQuery > 1.8 you can use even beforeunload instead.

The beforeunload event fires whenever the user leaves your page for any reason.

$(window).on("beforeunload", function() { 
    return confirm("Do you really want to close?"); 

Source Browser window close event

Get current date/time in seconds

I use this:

Math.round( / 1000)

No need for new object creation (see doc

New line character in VB.Net?

In for giving new line character in string you should use <br> .

For window base application Environment.NewLine will work fine.

Change icon on click (toggle)

Instead of overwriting the html every time, just toggle the class.

$('#click_advance').click(function() {
    $("i", this).toggleClass("icon-circle-arrow-up icon-circle-arrow-down");

How to display full (non-truncated) dataframe information in html when converting from pandas dataframe to html?

Set the display.max_colwidth option to None (or -1 before version 1.0):

pd.set_option('display.max_colwidth', None)

set_option docs

For example, in iPython, we see that the information is truncated to 50 characters. Anything in excess is ellipsized:

Truncated result

If you set the display.max_colwidth option, the information will be displayed fully:

Non-truncated result

java.lang.IllegalArgumentException: No converter found for return value of type

I had the very same problem, and unfortunately it could not be solved by adding getter methods, or adding jackson dependencies.

I then looked at Official Spring Guide, and followed their example as given here - - where the example also shows the conversion of returned object to JSON format.

I then again made my own project, with the difference that this time I also added the dependencies and build plugins that's present in the pom.xml file of the Official Spring Guide example I mentioned above.

The modified dependencies and build part of XML file looks like this!



You can see the same in the mentioned link above.

And magically, atleast for me, it works. So, if you have already exhausted your other options, you might want to try this out, as was the case with me.

Just a side note, it didn't work for me when I added the dependencies in my previous project and did Maven install and update project stuff. So, I had to again make my project from scratch. I didn't bother much about it as mine is an example project, but you might want to look for that too!

Display names of all constraints for a table in Oracle SQL

You need to query the data dictionary, specifically the USER_CONS_COLUMNS view to see the table columns and corresponding constraints:

  FROM user_cons_columns
 WHERE table_name = '<your table name>';

FYI, unless you specifically created your table with a lower case name (using double quotes) then the table name will be defaulted to upper case so ensure it is so in your query.

If you then wish to see more information about the constraint itself query the USER_CONSTRAINTS view:

  FROM user_constraints
 WHERE table_name = '<your table name>'
   AND constraint_name = '<your constraint name>';

If the table is held in a schema that is not your default schema then you might need to replace the views with:




adding to the where clause:

   AND owner = '<schema owner of the table>'

How to list all available Kafka brokers in a cluster?

echo dump | nc localhost 2181 | grep brokers

(replace localhost with the host where zookeeper is running)

Handling very large numbers in Python

The python interpreter will handle it for you, you just have to do your operations (+, -, *, /), and it will work as normal.

The int value is unlimited.

Careful when doing division, by default the quotient is turned into float, but float does not support such large numbers. If you get an error message saying float does not support such large numbers, then it means the quotient is too large to be stored in float you’ll have to use floor division (//).

It ignores any decimal that comes after the decimal point, this way, the result will be int, so you can have a large number result.



What is the better API to Reading Excel sheets in java - JXL or Apache POI

I have used both JXL (now "JExcel") and Apache POI. At first I used JXL, but now I use Apache POI.

First, here are the things where both APIs have the same end functionality:

  • Both are free
  • Cell styling: alignment, backgrounds (colors and patterns), borders (types and colors), font support (font names, colors, size, bold, italic, strikeout, underline)
  • Formulas
  • Hyperlinks
  • Merged cell regions
  • Size of rows and columns
  • Data formatting: Numbers and Dates
  • Text wrapping within cells
  • Freeze Panes
  • Header/Footer support
  • Read/Write existing and new spreadsheets
  • Both attempt to keep existing objects in spreadsheets they read in intact as far as possible.

However, there are many differences:

  • Perhaps the most significant difference is that Java JXL does not support the Excel 2007+ ".xlsx" format; it only supports the old BIFF (binary) ".xls" format. Apache POI supports both with a common design.
  • Additionally, the Java portion of the JXL API was last updated in 2009 (3 years, 4 months ago as I write this), although it looks like there is a C# API. Apache POI is actively maintained.
  • JXL doesn't support Conditional Formatting, Apache POI does, although this is not that significant, because you can conditionally format cells with your own code.
  • JXL doesn't support rich text formatting, i.e. different formatting within a text string; Apache POI does support it.
  • JXL only supports certain text rotations: horizontal/vertical, +/- 45 degrees, and stacked; Apache POI supports any integer number of degrees plus stacked.
  • JXL doesn't support drawing shapes; Apache POI does.
  • JXL supports most Page Setup settings such as Landscape/Portrait, Margins, Paper size, and Zoom. Apache POI supports all of that plus Repeating Rows and Columns.
  • JXL doesn't support Split Panes; Apache POI does.
  • JXL doesn't support Chart creation or manipulation; that support isn't there yet in Apache POI, but an API is slowly starting to form.
  • Apache POI has a more extensive set of documentation and examples available than JXL.

Additionally, POI contains not just the main "usermodel" API, but also an event-based API if all you want to do is read the spreadsheet content.

In conclusion, because of the better documentation, more features, active development, and Excel 2007+ format support, I use Apache POI.

Javascript callback when IFRAME is finished loading?

I've had exactly the same problem in the past and the only way I found to fix it was to add the callback into the iframe page. Of course that only works when you have control over the iframe content.

Adding images or videos to iPhone Simulator

Just to tell you : KONG's solution also works on iOS 7 beta.

His solution was:

Drag the image to simulator, then Safari opens (or browse to the Image in the internet using Safari) Hold your click on the image When the pop-up appears, choose Save Image and enjoy ;)

Send json post using php

use CURL luke :) seriously, thats one of the best ways to do it AND you get the response.

I am not able launch JNLP applications using "Java Web Start"?

Although this question is bit old, the issue was caused by corrupted ClearType registry setting and resolved by fixing it, as described in this ClearType, install4j and case of Java bug post.

ClearType, install4j and case of Java bug Java

Do you know what ClearType (font-smoothing technology in Windows) has in common with Java (programming language and one of the recommended frameworks)?

Nothing except that they were working together hard at making me miserable for few months. I had some Java software that I couldn’t install. I mean really couldn’t – not even figure out reason or reproduce it on another PC.

Recently I was approved for Woopra beta (site analytics service) and it uses desktop client written in Java… I couldn’t install. That got me really mad. :)

Story All of the software in question was similar :

setup based on install4j; setup crashing with bunch of errors. I was blaming install4j during early (hundred or so) attempts to solve issue. Later I slowly understood that if it was that bugged for that long time – solution would have been created and googled.

Tracing After shifting focus from install4j I decided to push Java framework. I was trying stable versions earlier so decided to go for non-stable 1.6 Update 10 Release Candidate.

This actually fixed error messages but not crashes. I had also noticed that there was new error log created in directory with setup files. Previously I had only seen logs in Windows temporary directory.

New error log was saying following :

Could not display the GUI. This application needs access to an X Server. If you have access there is probably an X library missing. ******************************************************************* You can also run this application in console mode without access to an X server by passing the argument -c Very weird to look for X-Server on non-Linux PC, isn’t it? So I decided to try that “-c” argument. And was actually able to install in console mode.

Happy ending? Nope. Now installed app was crashing. But it really got me thinking. If console works but graphical interface doesn’t – there must be problem with latter.

One more error log (in application folder) was now saying (among other things) :

Caused by: java.lang.IllegalArgumentException: -60397977 incompatible with Text-specific LCD contrast key Which successfully googled me description of bug with Java unable to read non-standard ClearType registry setting.

Solution I immediately launched ClearType Tuner from Control Panel and found setting showing gibberish number. After correcting it to proper one all problems with Java were instantly gone.

cleartypetuner_screenshot Lessons learned Don’t be fast to blame software problems on single application. Even minor and totally unrelated settings can launch deadly chain reactions. Links Jave Runtime Environment

ClearType Tuner



How to convert a pandas DataFrame subset of columns AND rows into a numpy array?

.loc accept row and column selectors simultaneously (as do .ix/.iloc FYI) This is done in a single pass as well.

In [1]: df = DataFrame(np.random.rand(4,5), columns = list('abcde'))

In [2]: df
          a         b         c         d         e
0  0.669701  0.780497  0.955690  0.451573  0.232194
1  0.952762  0.585579  0.890801  0.643251  0.556220
2  0.900713  0.790938  0.952628  0.505775  0.582365
3  0.994205  0.330560  0.286694  0.125061  0.575153

In [5]: df.loc[df['c']>0.5,['a','d']]
          a         d
0  0.669701  0.451573
1  0.952762  0.643251
2  0.900713  0.505775

And if you want the values (though this should pass directly to sklearn as is); frames support the array interface

In [6]: df.loc[df['c']>0.5,['a','d']].values
array([[ 0.66970138,  0.45157274],
       [ 0.95276167,  0.64325143],
       [ 0.90071271,  0.50577509]])

How can I upgrade NumPy?

All the same.

   sudo easy_install numpy

My Traceback

Searching for numpy

Best match: numpy 1.13.0

Adding numpy 1.13.0 to easy-install.pth file

Using /Library/Python/2.7/site-packages

Processing dependencies for numpy

Console.log(); How to & Debugging javascript

I like to add these functions in the head.

jQuery.fn.log=function (msg){console.log("%s: %o", msg,this);return this;};

Now log won't break IE I can enable it or disable it in one place I can log inline

$(".classname").log(); //show an array of all elements with classname class

Git: How to commit a manually deleted file?

It says right there in the output of git status:

#   (use "git add/rm <file>..." to update what will be committed)

so just do:

git rm <filename>

substring of an entire column in pandas dataframe

case the column isn't string, use astype to convert:

df['col'] = df['col'].astype(str).str[:9]

Does JavaScript have a built in stringbuilder class?

When I find myself doing a lot of string concatenation in JavaScript, I start looking for templating. Handlebars.js works quite well keeping the HTML and JavaScript more readable.

How to compile Tensorflow with SSE4.2 and AVX instructions?

I have recently installed it from source and bellow are all the steps needed to install it from source with the mentioned instructions available.

Other answers already describe why those messages are shown. My answer gives a step-by-step on how to isnstall, which may help people struglling on the actual installation as I did.

  1. Install Bazel

Download it from one of their available releases, for example 0.5.2. Extract it, go into the directory and configure it: bash ./ Copy the executable to /usr/local/bin: sudo cp ./output/bazel /usr/local/bin

  1. Install Tensorflow

Clone tensorflow: git clone Go to the cloned directory to configure it: ./configure

It will prompt you with several questions, bellow I have suggested the response to each of the questions, you can, of course, choose your own responses upon as you prefer:

Using python library path: /usr/local/lib/python2.7/dist-packages
Do you wish to build TensorFlow with MKL support? [y/N] y
MKL support will be enabled for TensorFlow
Do you wish to download MKL LIB from the web? [Y/n] Y
Please specify optimization flags to use during compilation when bazel option "--config=opt" is specified [Default is -march=native]: 
Do you wish to use jemalloc as the malloc implementation? [Y/n] n
jemalloc disabled
Do you wish to build TensorFlow with Google Cloud Platform support? [y/N] N
No Google Cloud Platform support will be enabled for TensorFlow
Do you wish to build TensorFlow with Hadoop File System support? [y/N] N
No Hadoop File System support will be enabled for TensorFlow
Do you wish to build TensorFlow with the XLA just-in-time compiler (experimental)? [y/N] N
No XLA JIT support will be enabled for TensorFlow
Do you wish to build TensorFlow with VERBS support? [y/N] N
No VERBS support will be enabled for TensorFlow
Do you wish to build TensorFlow with OpenCL support? [y/N] N
No OpenCL support will be enabled for TensorFlow
Do you wish to build TensorFlow with CUDA support? [y/N] N
No CUDA support will be enabled for TensorFlow
  1. The pip package. To build it you have to describe which instructions you want (you know, those Tensorflow informed you are missing).

Build pip script: bazel build -c opt --copt=-mavx --copt=-mavx2 --copt=-mfma --copt=-mfpmath=both --copt=-msse4.1 --copt=-msse4.2 -k //tensorflow/tools/pip_package:build_pip_package

Build pip package: bazel-bin/tensorflow/tools/pip_package/build_pip_package /tmp/tensorflow_pkg

Install Tensorflow pip package you just built: sudo pip install /tmp/tensorflow_pkg/tensorflow-1.2.1-cp27-cp27mu-linux_x86_64.whl

Now next time you start up Tensorflow it will not complain anymore about missing instructions.

MySQL select 10 random rows from 600K rows fast

Use the below simple query to get random data from a table.

SELECT user_firstname ,
COUNT(DISTINCT usr_fk_id) cnt
FROM userdetails 
GROUP BY usr_fk_id 

How to check if a line is blank using regex

Well...I tinkered around (using notepadd++) and this is the solution I found


\n for end of line (where you start matching) -- the caret would not be of help in my case as the beginning of the row is a string \s takes any space till the next string

hope it helps

React Native absolute positioning horizontal centre

Wrap the child you want centered in a View and make the View absolute.

<View style={{position: 'absolute', top: 0, left: 0, right: 0, bottom: 0, justifyContent: 'center', alignItems: 'center'}}>
  <Text>Centered text</Text>

how to get param in method post spring mvc?

  1. Spring annotations will work fine if you remove enctype="multipart/form-data".

    @RequestParam(value="txtEmail", required=false)
  2. You can even get the parameters from the request object .

  3. Use a form in case the number of attributes are large. It will be convenient. Tutorial to get you started.

  4. Configure the Multi-part resolver if you want to receive enctype="multipart/form-data".

    <bean id="multipartResolver"
        <property name="maxUploadSize" value="250000"/>

Refer the Spring documentation.

Left align and right align within div in Bootstrap

We can achieve by Bootstrap 4 Flexbox:

<div class="d-flex justify-content-between w-100">
<p>TotalCost</p> <p>$42</p>

d-flex // Display Flex
justify-content-between // justify-content:space-between
w-100 // width:100%

Example: JSFiddle

Java String to Date object of the format "yyyy-mm-dd HH:mm:ss"

its work for me SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); sdf.format(new Date));

How to return multiple values?

You can return an object of a Class in Java.

If you are returning more than 1 value that are related, then it makes sense to encapsulate them into a class and then return an object of that class.

If you want to return unrelated values, then you can use Java's built-in container classes like Map, List, Set etc. Check the java.util package's JavaDoc for more details.

Each for object?

A javascript Object does not have a standard .each function. jQuery provides a function. See The below should work

$.each(object, function(index, value) {

Another option would be to use vanilla Javascript using the Object.keys() and the Array .map() functions like this

Object.keys(object).map(function(objectKey, index) {
    var value = object[objectKey];

See and

These are usually better than using a vanilla Javascript for-loop, unless you really understand the implications of using a normal for-loop and see use for it's specific characteristics like looping over the property chain.

But usually, a for-loop doesn't work better than jQuery or Object.keys().map(). I'll go into two potential issues with using a plain for-loop below.

Right, so also pointed out in other answers, a plain Javascript alternative would be

for(var index in object) { 
    var attr = object[index]; 

There are two potential issues with this:

1 . You want to check whether the attribute that you are finding is from the object itself and not from up the prototype chain. This can be checked with the hasOwnProperty function like so

for(var index in object) { 
   if (object.hasOwnProperty(index)) {
       var attr = object[index];

See for more information.

The jQuery.each and Object.keys functions take care of this automatically.

2 . Another potential issue with a plain for-loop is that of scope and non-closures. This is a bit complicated, but take for example the following code. We have a bunch of buttons with ids button0, button1, button2 etc, and we want to set an onclick on them and do a console.log like this:

<button id='button0'>click</button>
<button id='button1'>click</button>
<button id='button2'>click</button>

var messagesByButtonId = {"button0" : "clicked first!", "button1" : "clicked middle!", "button2" : "clicked last!"];
for(var buttonId in messagesByButtonId ) { 
   if (messagesByButtonId.hasOwnProperty(buttonId)) {
       $('#'+buttonId).click(function() {
           var message = messagesByButtonId[buttonId];

If, after some time, we click any of the buttons we will always get "clicked last!" in the console, and never "clicked first!" or "clicked middle!". Why? Because at the time that the onclick function is executed, it will display messagesByButtonId[buttonId] using the buttonId variable at that moment. And since the loop has finished at that moment, the buttonId variable will still be "button2" (the value it had during the last loop iteration), and so messagesByButtonId[buttonId] will be messagesByButtonId["button2"], i.e. "clicked last!".

See for more information on closures. Especially the last part of that page that covers our example.

Again, jQuery.each and Object.keys().map() solve this problem automatically for us, because it provides us with a function(index, value) (that has closure) so we are safe to use both index and value and rest assured that they have the value that we expect.

How to append multiple items in one line in Python

use for loop. like this:

for x in [1,2,7,8,9,10,13,14,19,20,21,22]:
    new_list.append(my_list[i + x])

Java 8 - Difference between Optional.flatMap and


Takes every element and if the value exists, it is passed to the function:

Optional<T> optionalValue = ...;
Optional<Boolean> added =;

Now added has one of three values: true or false wrapped into an Optional , if optionalValue was present, or an empty Optional otherwise.

If you don't need to process the result you can simply use ifPresent(), it doesn't have return value:

  • Optional.flatMap():

Works similar to the same method of streams. Flattens out the stream of streams. With the difference that if the value is presented it is applied to function. Otherwise, an empty optional is returned.

You can use it for composing optional value functions calls.

Suppose we have methods:

public static Optional<Double> inverse(Double x) {
    return x == 0 ? Optional.empty() : Optional.of(1 / x);

public static Optional<Double> squareRoot(Double x) {
    return x < 0 ? Optional.empty() : Optional.of(Math.sqrt(x));

Then you can compute the square root of the inverse, like:

Optional<Double> result = inverse(-4.0).flatMap(MyMath::squareRoot);

or, if you prefer:

Optional<Double> result = Optional.of(-4.0).flatMap(MyMath::inverse).flatMap(MyMath::squareRoot);

If either the inverse() or the squareRoot() returns Optional.empty(), the result is empty.

JUnit tests pass in Eclipse but fail in Maven Surefire

I have the similar problem, but with IntelliJ IDEA + Maven + TestNG + spring-test. (spring-test is essential of course :) ) It was fixed when I've change config of maven-surefire-plugin to disable run tests in parallel. Like this:

        <!-- to skip integration tests -->
                <!-- Make sure to include this part, since otherwise it is excluding Integration tests -->

How to use onResume()?

onResume() is one of the methods called throughout the activity lifecycle. onResume() is the counterpart to onPause() which is called anytime an activity is hidden from view, e.g. if you start a new activity that hides it. onResume() is called when the activity that was hidden comes back to view on the screen.

You're question asks abou what method is used to restart an activity. onCreate() is called when the activity is first created. In practice, most activities persist in the background through a series of onPause() and onResume() calls. An activity is only really "restarted" by onRestart() if it is first fully stopped by calling onStop() and then brought back to life. Thus if you are not actually stopping activities with onStop() it is most likley you will be using onResume().

Read the android doc in the above link to get a better understanding of the relationship between the different lifestyle methods. Regardless of which lifecycle method you end up using the general format is the same. You must override the standard method and include your code, i.e. what you want the activity to do at that point, in the commented section.

public void onResume(){
 //will be executed onResume

Download file through an ajax call php

You can't download the file directly via ajax.

You can put a link on the page with the URL to your file (returned from the ajax call) or another way is to use a hidden iframe and set the URL of the source of that iframe dynamically. This way you can download the file without refreshing the page.

Here is the code

    url : "yourURL.php",
    type : "GET",
    success : function(data) {
        $("#iframeID").attr('src', 'downloadFileURL');

Different ways of adding to Dictionary

One is assigning a value while the other is adding to the Dictionary a new Key and Value.

How do you access the element HTML from within an Angular attribute directive?

So actually, my comment that you should do a console.log(el.nativeElement) should have pointed you in the right direction, but I didn't expect the output to be just a string representing the DOM Element.

What you have to do to inspect it in the way it helps you with your problem, is to do a console.log(el) in your example, then you'll have access to the nativeElement object and will see a property called innerHTML.

Which will lead to the answer to your original question:

let myCurrentContent:string = el.nativeElement.innerHTML; // get the content of your element
el.nativeElement.innerHTML = 'my new content'; // set content of your element

Update for better approach:

Since it's the accepted answer and web workers are getting more important day to day (and it's considered best practice anyway) I want to add this suggestion by Mark Rajcok here.

The best way to manipulate DOM Elements programmatically is using the Renderer:

constructor(private _elemRef: ElementRef, private _renderer: Renderer) { 
    this._renderer.setElementProperty(this._elemRef.nativeElement, 'innerHTML', 'my new content');


Since Renderer is deprecated now, use Renderer2 instead with setProperty


This question with its answer explained the console.log behavior.

Which means that console.dir(el.nativeElement) would be the more direct way of accessing the DOM Element as an "inspectable" Object in your console for this situation.

Hope this helped.

trigger body click with jQuery

if all things were said didn't work, go back to basics and test if this is working:

    <script type="text/javascript" src=""></script>
    <script type="text/javascript">
      $('body').click(function() {
        // do something here like:
        alert('hey! The body click is working!!!')

then tell me if its working or not.

Getting a 'source: not found' error when using source in a bash script

In the POSIX standard, which /bin/sh is supposed to respect, the command is . (a single dot), not source. The source command is a csh-ism that has been pulled into bash.


. $env_name/bin/activate

Or if you must have non-POSIX bash-isms in your code, use #!/bin/bash.

How to make ng-repeat filter out duplicate results

I had an array of strings, not objects and i used this approach:

ng-repeat="name in names | unique"

with this filter:

angular.module('app').filter('unique', unique);
function unique(){
return function(arry){
        Array.prototype.getUnique = function(){
        var u = {}, a = [];
        for(var i = 0, l = this.length; i < l; ++i){
           if(u.hasOwnProperty(this[i])) {
           u[this[i]] = 1;
        return a;
    if(arry === undefined || arry.length === 0){
          return '';
    else {
         return arry.getUnique(); 


How to use sed to extract substring

You want awk.

This would be a quick and dirty hack:

awk -F "\"" '{print $2}' /tmp/file.txt


Ruby capitalize every word first letter

If you are trying to capitalize the first letter of each word in an array you can simply put this:

What is the best way to repeatedly execute a function every x seconds?

One possible answer:

import time

while True:
    if time.time()-t>10:
        #run your task here

ORA-01036: illegal variable name/number when running query through C#

Just for others getting this error and looking for info on it, it is also thrown if you happen to pass a binding parameter and then never use it. I couldn't really find that stated clearly anywhere but had to prove it through trial and error.

SQL QUERY replace NULL value in a row with a value from the previous known value

Here's a MySQL solution:

UPDATE mytable
SET number = (@n := COALESCE(number, @n))
ORDER BY date;

This is concise, but won't necessary work in other brands of RDBMS. For other brands, there might be a brand-specific solution that is more relevant. That's why it's important to tell us the brand you're using.

It's nice to be vendor-independent, as @Pax commented, but failing that, it's also nice to use your chosen brand of database to its fullest advantage.

Explanation of the above query:

@n is a MySQL user variable. It starts out NULL, and is assigned a value on each row as the UPDATE runs through rows. Where number is non-NULL, @n is assigned the value of number. Where number is NULL, the COALESCE() defaults to the previous value of @n. In either case, this becomes the new value of the number column and the UPDATE proceeds to the next row. The @n variable retains its value from row to row, so subsequent rows get values that come from the prior row(s). The order of the UPDATE is predictable, because of MySQL's special use of ORDER BY with UPDATE (this is not standard SQL).

How to call C++ function from C?

#include <iostream>

// C++ code //
struct A
  int i;
  int j;

  A() {i=1; j=2; std::cout << "class A created\n";}
  void dump() {std::cout << "class A dumped: " << i << ":" << j << std::endl;}
  ~A() {std::cout << "class A destroyed\n";}

extern "C" {
  // this is the C code interface to the class A
  static void *createA (void)
    // create a handle to the A class
    return (void *)(new A);
  static void dumpA (void *thisPtr)
    // call A->dump ()
    if (thisPtr != NULL) // I'm an anal retentive programmer
      A *classPtr = static_cast<A *>(thisPtr);
      classPtr->dump ();
  static void *deleteA (void *thisPtr)
    // destroy the A class
    if (thisPtr != NULL)
      delete (static_cast<A *>(thisPtr));

// this can be compiled as C code //
int main (int argc, char **argv)
  void *handle = createA();

  dumpA (handle);
  deleteA (handle);

  return 0;

Best way to incorporate Volley (or other library) into Android Studio project

As of today, there is an official Android-hosted copy of Volley available on JCenter:

compile ''

This was compiled from the AOSP volley source code.

Batch script loop

And to iterate on the files of a directory:

@echo off 
setlocal enableDelayedExpansion 

set MYDIR=C:\something
for /F %%x in ('dir /B/D %MYDIR%') do (
  set FILENAME=%MYDIR%\%%x\log\IL_ERROR.log
  echo ===========================  Search in !FILENAME! ===========================
  c:\utils\grep motiv !FILENAME!

You must use "enableDelayedExpansion" and !FILENAME! instead of $FILENAME$. In the second case, DOS will interpret the variable only once (before it enters the loop) and not each time the program loops.

Why do abstract classes in Java have constructors?

Implementation wise you will often see inside super() statement in subclasses constructors, something like:

public class A extends AbstractB{

  public A(...){
     super(String constructorArgForB, ...);

Excel VBA to Export Selected Sheets to PDF

Once you have Selected a group of sheets, you can use Selection


Sub luxation()
    ThisWorkbook.Sheets(Array("Sheet1", "Sheet2", "Sheet3")).Select
    Selection.ExportAsFixedFormat _
        Type:=xlTypePDF, _
        Filename:="C:\TestFolder\temp.pdf", _
        Quality:=xlQualityStandard, _
        IncludeDocProperties:=True, _
        IgnorePrintAreas:=False, _
End Sub


Further testing has reveled that this technique depends on the group of cells selected on each worksheet. To get a comprehensive output, use something like:

Sub Macro1()


   ThisWorkbook.Sheets(Array("Sheet1", "Sheet2", "Sheet3")).Select
   Selection.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
      "C:\Users\James\Desktop\pdfmaker.pdf", Quality:=xlQualityStandard, _
      IncludeDocProperties:=True, IgnorePrintAreas:=False, OpenAfterPublish:= _
End Sub

How to subtract a day from a date?

Subtract datetime.timedelta(days=1)

How to get last month/year in java?

Use Joda Time Library. It is very easy to handle date, time, calender and locale with it and it will be integrated to java in version 8.

DateTime#minusMonths method would help you get previous month.

DateTime month = new DateTime().minusMonths (1); 

git stash blunder: git stash pop and ended up with merge conflicts

Note that Git 2.5 (Q2 2015) a future Git might try to make that scenario impossible.

See commit ed178ef by Jeff King (peff), 22 Apr 2015.
(Merged by Junio C Hamano -- gitster -- in commit 05c3967, 19 May 2015)

Note: This has been reverted. See below.

stash: require a clean index to apply/pop


If you have staged contents in your index and run "stash apply/pop", we may hit a conflict and put new entries into the index.
Recovering to your original state is difficult at that point, because tools like "git reset --keep" will blow away anything staged.

In other words:

"git stash pop/apply" forgot to make sure that not just the working tree is clean but also the index is clean.
The latter is important as a stash application can conflict and the index will be used for conflict resolution.


We can make this safer by refusing to apply when there are staged changes.

That means if there were merges before because of applying a stash on modified files (added but not committed), now they would not be any merges because the stash apply/pop would stop immediately with:

Cannot apply stash: Your index contains uncommitted changes.

Forcing you to commit the changes means that, in case of merges, you can easily restore the initial state( before git stash apply/pop) with a git reset --hard.

See commit 1937610 (15 Jun 2015), and commit ed178ef (22 Apr 2015) by Jeff King (peff).
(Merged by Junio C Hamano -- gitster -- in commit bfb539b, 24 Jun 2015)

That commit was an attempt to improve the safety of applying a stash, because the application process may create conflicted index entries, after which it is hard to restore the original index state.

Unfortunately, this hurts some common workflows around "git stash -k", like:

git add -p       ;# (1) stage set of proposed changes
git stash -k     ;# (2) get rid of everything else
make test        ;# (3) make sure proposal is reasonable
git stash apply  ;# (4) restore original working tree

If you "git commit" between steps (3) and (4), then this just works. However, if these steps are part of a pre-commit hook, you don't have that opportunity (you have to restore the original state regardless of whether the tests passed or failed).

Easiest way to read/write a file's content in Python

If you're open to using libraries, try installing forked-path (with either easy_install or pip).

Then you can do:

from path import path
s = path(filename).bytes()

This library is fairly new, but it's a fork of a library that's been floating around Python for years and has been used quite a bit. Since I found this library years ago, I very seldom use os.path or open() any more.

How to hash some string with sha256 in Java?

Full example hash to string as another string.

public static String sha256(String base) {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        byte[] hash = digest.digest(base.getBytes("UTF-8"));
        StringBuffer hexString = new StringBuffer();

        for (int i = 0; i < hash.length; i++) {
            String hex = Integer.toHexString(0xff & hash[i]);
            if(hex.length() == 1) hexString.append('0');

        return hexString.toString();
    } catch(Exception ex){
       throw new RuntimeException(ex);

Dockerfile copy keep subdirectory structure

If you want to copy a source directory entirely with the same directory structure, Then don't use a star(*). Write COPY command in Dockerfile as below.

COPY . destinatio-directory/ 

How to get images in Bootstrap's card to be the same height/width?

.card-img-top {
    height: 15rem;
    object-fit: cover;

ggplot with 2 y axes on each side and different scales

I acknowledge and agree with hadley (and others), that separate y-scales are "fundamentally flawed". Having said that – I often wish ggplot2 had the feature – particularly, when the data is in wide-format and I quickly want to visualise or check the data (i.e. for personal use only).

While the tidyverse library makes it fairly easy to convert the data to long-format (such that facet_grid() will work), the process is still not trivial, as seen below:

df.wide %>%
    # Select only the columns you need for the plot.
    select(date, column1, column2, column3) %>%
    # Create an id column – needed in the `gather()` function.
    mutate(id = n()) %>%
    # The `gather()` function converts to long-format. 
    # In which the `type` column will contain three factors (column1, column2, column3),
    # and the `value` column will contain the respective values.
    # All the while we retain the `id` and `date` columns.
    gather(type, value, -id, -date) %>%
    # Create the plot according to your specifications
    ggplot(aes(x = date, y = value)) +
        geom_line() +
        # Create a panel for each `type` (ie. column1, column2, column3).
        # If the types have different scales, you can use the `scales="free"` option.
        facet_grid(type~., scales = "free")

n-grams in python, four, five, six grams?

Great native python based answers given by other users. But here's the nltk approach (just in case, the OP gets penalized for reinventing what's already existing in the nltk library).

There is an ngram module that people seldom use in nltk. It's not because it's hard to read ngrams, but training a model base on ngrams where n > 3 will result in much data sparsity.

from nltk import ngrams

sentence = 'this is a foo bar sentences and i want to ngramize it'

n = 6
sixgrams = ngrams(sentence.split(), n)

for grams in sixgrams:
  print grams

UnicodeDecodeError when reading CSV file in Pandas with Python

Sometimes the problem is with the .csv file only. The file may be corrupted. When faced with this issue. 'Save As' the file as csv again.

0. Open the xls/csv file
1. Go to -> files 
2. Click -> Save As 
3. Write the file name 
4. Choose 'file type' as -> CSV [very important]
5. Click -> Ok 

File Upload to HTTP server in iphone programming

ASIHTTPRequest is a great wrapper around the network APIs and makes it very easy to upload a file. Here's their example (but you can do this on the iPhone too - we save images to "disk" and later upload them.

ASIFormDataRequest *request = [[[ASIFormDataRequest alloc] initWithURL:url] autorelease];
[request setPostValue:@"Ben" forKey:@"first_name"];
[request setPostValue:@"Copsey" forKey:@"last_name"];
[request setFile:@"/Users/ben/Desktop/ben.jpg" forKey:@"photo"];

how does work?

It uses the slice method arrays have and calls it with its this being the arguments object. This means it calls it as if you did arguments.slice() assuming arguments had such a method.

Creating a slice without any arguments will simply take all elements - so it simply copies the elements from arguments to an array.

How to center and crop an image to always appear in square shape with CSS?

object-fit property does the magic. On JsFiddle.


.image {
  width: 160px;
  height: 160px;

.object-fit_fill {
  object-fit: fill

.object-fit_contain {
  object-fit: contain

.object-fit_cover {
  object-fit: cover

.object-fit_none {
  object-fit: none

.object-fit_scale-down {
  object-fit: scale-down


<div class="original-image">
  <p>original image</p>
  <img src="">

<div class="image">
  <p>object-fit: fill</p>
  <img class="object-fit_fill" src="">

<div class="image">
  <p>object-fit: contain</p>
  <img class="object-fit_contain" src="">

<div class="image">
  <p>object-fit: cover</p>
  <img class="object-fit_cover" src="">

<div class="image">
  <p>object-fit: none</p>
  <img class="object-fit_none" src="">

<div class="image">
  <p>object-fit: scale-down</p>
  <img class="object-fit_scale-down" src="">


How the rendered images look (in a browser that supports <code>object-fit</code>)

Min and max value of input in angular4 application

Simply do this in angular2+ by adding (onkeypress)

<input type="number" 
    (onkeypress)="return (event.charCode == 8 || event.charCode == 0) ? null : event.charCode >= 48 && event.charCode <= 57"

Tested on Angular 7

How do I set up the database.yml file in Rails?

The database.yml is the file where you set up all the information to connect to the database. It differs depending on the kind of DB you use. You can find more information about this in the Rails Guide or any tutorial explaining how to setup a rails project.

The information in the database.yml file is scoped by environment, allowing you to get a different setting for testing, development or production. It is important that you keep those distinct if you don't want the data you use for development deleted by mistake while running your test suite.

Regarding source control, you should not commit this file but instead create a template file for other developers (called database.yml.template). When deploying, the convention is to create this database.yml file in /shared/config directly on the server.

With SVN: svn propset svn:ignore config "database.yml"

With Git: Add config/database.yml to the .gitignore file or with git-extra git ignore config/database.yml

... and now, some examples:


adapter: sqlite3
database: db/db_dev_db.sqlite3
pool: 5
timeout: 5000


adapter: mysql
database: my_db
username: root
socket: /tmp/mysql.sock
pool: 5
timeout: 5000

MongoDB with MongoID (called mongoid.yml, but basically the same thing)

host: <%= ENV['MONGOID_HOST'] %>
port: <%= ENV['MONGOID_PORT'] %>
username: <%= ENV['MONGOID_USERNAME'] %>
password: <%= ENV['MONGOID_PASSWORD'] %>
database: <%= ENV['MONGOID_DATABASE'] %>
# slaves:
#   - host: slave1.local
#     port: 27018
#   - host: slave2.local
#     port: 27019

How to read all files in a folder from Java?

 * Function to read all mp3 files from sdcard and store the details in an
 * ArrayList

public ArrayList<HashMap<String, String>> getPlayList() 
        ArrayList<HashMap<String, String>> songsList=new ArrayList<>();
        File home = new File(MEDIA_PATH);

        if (home.listFiles(new FileExtensionFilter()).length > 0) {
            for (File file : home.listFiles(new FileExtensionFilter())) {
                HashMap<String, String> song = new HashMap<String, String>();
                                (file.getName().length() - 4)));
                song.put("songPath", file.getPath());

                // Adding each song to SongList
        // return songs list array
        return songsList;

     * Class to filter files which have a .mp3 extension
     * */
    class FileExtensionFilter implements FilenameFilter 
        public boolean accept(File dir, String name) {
            return (name.endsWith(".mp3") || name.endsWith(".MP3"));

You can filter any textfiles or any other extension ..just replace it with .MP3

Flutter: RenderBox was not laid out


I used this code to fix the issue of displaying items in the horizontal list.

new Container(
      height: 20,
      child: Row(
        mainAxisAlignment: MainAxisAlignment.end,
        children: <Widget>[
            scrollDirection: Axis.horizontal,
            shrinkWrap: true,
            itemCount: array.length,
            itemBuilder: (context, index){
              return array[index];

append multiple values for one key in a dictionary

You can use setdefault.

for line in list:  
    d.setdefault(year, []).append(value)

This works because setdefault returns the list as well as setting it on the dictionary, and because a list is mutable, appending to the version returned by setdefault is the same as appending it to the version inside the dictionary itself. If that makes any sense.

Android - Pulling SQlite database android device

For Ubuntu (not only?):

see Sergeis Answer but instead of openssl use zlib-flate:

cat appbackup.ab | (dd bs=24 count=0 skip=1; cat) | zlib-flate -uncompress > appbackup.tar

Otherwise openssl will probably throw:

openssl:Error: 'zlib' is an invalid command.

because openssl is not compiled with zlib support in Ubuntu

How do I select an element with its name attribute in jQuery?

it's very simple getting a name:


Resource: (google search: get element by name jQuery - first result)

What to use instead of "addPreferencesFromResource" in a PreferenceActivity?

No alternative method is provided in the method's description because the preferred approach (as of API level 11) is to instantiate PreferenceFragment objects to load your preferences from a resource file. See the sample code here: PreferenceActivity

Force HTML5 youtube video

I tried using the iframe embed code and the HTML5 player appeared, however, for some reason the iframe was completely breaking my site.

I messed around with the old object embed code and it works perfectly fine. So if you're having problems with the iframe here's the code i used:

<object width="640" height="360">
<param name="movie" value=";rel=0&amp;hl=en_US&amp;version=3"/>
<param name="allowFullScreen" value="true"/>
<param name="allowscriptaccess" value="always"/>
<embed width="640" height="360" src=";rel=0&amp;hl=en_US&amp;version=3" class="youtube-player" type="text/html" allowscriptaccess="always" allowfullscreen="true"/>

hope this is useful for someone

Changing precision of numeric column in Oracle

Assuming that you didn't set a precision initially, it's assumed to be the maximum (38). You're reducing the precision because you're changing it from 38 to 14.

The easiest way to handle this is to rename the column, copy the data over, then drop the original column:

alter table EVAPP_FEES rename column AMOUNT to AMOUNT_OLD;

alter table EVAPP_FEES add AMOUNT NUMBER(14,2);


alter table EVAPP_FEES drop column AMOUNT_OLD;

If you really want to retain the column ordering, you can move the data twice instead:

alter table EVAPP_FEES add AMOUNT_TEMP NUMBER(14,2);


update EVAPP_FEES set AMOUNT = null;

alter table EVAPP_FEES modify AMOUNT NUMBER(14,2);


alter table EVAPP_FEES drop column AMOUNT_TEMP;

Insert Unicode character into JavaScript

One option is to put the character literally in your script, e.g.:

const omega = 'O';

This requires that you let the browser know the correct source encoding, see Unicode in JavaScript

However, if you can't or don't want to do this (e.g. because the character is too exotic and can't be expected to be available in the code editor font), the safest option may be to use new-style string escape or String.fromCodePoint:

const omega = '\u{3a9}';

// or:

const omega = String.fromCodePoint(0x3a9);

This is not restricted to UTF-16 but works for all unicode code points. In comparison, the other approaches mentioned here have the following downsides:

  • HTML escapes (const omega = '&#937';): only work when rendered unescaped in an HTML element
  • old style string escapes (const omega = '\u03A9';): restricted to UTF-16
  • String.fromCharCode: restricted to UTF-16

What is the difference between HTTP status code 200 (cache) vs status code 304?

For your last question, why ? I'll try to explain with what I know

A brief explanation of those three status codes in layman's terms.

  • 200 - success (browser requests and get file from server)

If caching is enabled in the server

  • 200 (from memory cache) - file found in browser, so browser is not going request from server
  • 304 - browser request a file but it is rejected by server

For some files browser is deciding to request from server and for some it's deciding to read from stored (cached) files. Why is this ? Every files has an expiry date, so

If a file is not expired then the browser will use from cache (200 cache).

If file is expired, browser requests server for a file. Server check file in both places (browser and server). If same file found, server refuses the request. As per protocol browser uses existing file.

look at this nginx configuration

location / {
    add_header Cache-Control must-revalidate;
    expires     60;
    etag on;


Here the expiry is set to 60 seconds, so all static files are cached for 60 seconds. So if u request a file again within 60 seconds browser will read from memory (200 memory). If u request after 60 seconds browser will request server (304).

I assumed that the file is not changed after 60 seconds, in that case you would get 200 (ie, updated file will be fetched from server).

So, if the servers are configured with different expiring and caching headers (policies), the status may differ.

In your case you are using cdn, the main purpose of cdn is high availability and fast delivery. Therefore they use multiple servers. Even though it seems like files are in same directory, cdn might use multiple servers to provide u content, if those servers have different configurations. Then these status can change. Hope it helps.

Horizontal scroll on overflow of table

The solution for those who cannot or do not want to wrap the table in a div (e.g. if the HTML is generated from Markdown) but still want to have scrollbars:

table {_x000D_
  display: block;_x000D_
  max-width: -moz-fit-content;_x000D_
  max-width: fit-content;_x000D_
  margin: 0 auto;_x000D_
  overflow-x: auto;_x000D_
  white-space: nowrap;_x000D_
    <td>Especially on mobile, a table can easily become wider than the viewport.</td>_x000D_
    <td>Using the right CSS, you can get scrollbars on the table without wrapping it.</td>_x000D_
    <td>A centered table.</td>_x000D_

Explanation: display: block; makes it possible to have scrollbars. By default (and unlike tables), blocks span the full width of the parent element. This can be prevented with max-width: fit-content;, which allows you to still horizontally center tables with less content using margin: 0 auto;. white-space: nowrap; is optional (but useful for this demonstration).

Difference between angle bracket < > and double quotes " " while including header files in C++?

It's compiler dependent. That said, in general using " prioritizes headers in the current working directory over system headers. <> usually is used for system headers. From to the specification (Section 6.10.2):

A preprocessing directive of the form

  # include <h-char-sequence> new-line

searches a sequence of implementation-defined places for a header identified uniquely by the specified sequence between the < and > delimiters, and causes the replacement of that directive by the entire contents of the header. How the places are specified or the header identified is implementation-defined.

A preprocessing directive of the form

  # include "q-char-sequence" new-line

causes the replacement of that directive by the entire contents of the source file identified by the specified sequence between the " delimiters. The named source file is searched for in an implementation-defined manner. If this search is not supported, or if the search fails, the directive is reprocessed as if it read

  # include <h-char-sequence> new-line

with the identical contained sequence (including > characters, if any) from the original directive.

So on most compilers, using the "" first checks your local directory, and if it doesn't find a match then moves on to check the system paths. Using <> starts the search with system headers.

Repeat a string in JavaScript a number of times

String.prototype.repeat = function (n) { n = Math.abs(n) || 1; return Array(n + 1).join(this || ''); };

// console.log("0".repeat(3) , "0".repeat(-3))
// return: "000" "000"

NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

i had the same error while working with hibernate, i had added below dependency in my pom.xml that solved the problem



How to convert IPython notebooks to PDF and HTML?

nbconvert is not yet fully replaced by nbconvert2, you can still use it if you wish, otherwise we would have removed the executable. It's just a warning that we do not bugfix nbconvert1 anymore.

The following should work :

./ --format=pdf yourfile.ipynb 

If you are on a IPython recent enough version, do not use print view, just use the the normal print dialog. Graph beeing cut in chrome is a known issue (Chrome does not respect some print css), and works much better with firefox, not all versions still.

As for nbconvert2, it still highly dev and docs need to be written.

Nbviewer use nbconvert2 so it's pretty decent with HTML.

List of current available profiles:

$ ls -l1 profile|cut -d. -f1


Give you the existing profiles. (You can create your own, cf future doc, ./ --help-all should give you some option you can use in your profile.)


$ ./ [profilename] --no-stdout --write=True <yourfile.ipynb>

And it should write your (tex) files as long as extracted figures in cwd. Yes I know this is not obvious, and it will probably change hence no doc...

The reason for that is that nbconvert2 will mainly be a python library where in pseudo code you can do :

 MyConverter = NBConverter(config=config)
 ipynb = read(ipynb_file)
 converted_files = MyConverter.convert(ipynb)
 for file in converted_files :

Entry point will come later, once the API is stabilized.

I'll just point out that @jdfreder (github profile) is working on tex/pdf/sphinx export and is the expert to generate PDF from ipynb file at the time of this writing.

Chrome not rendering SVG referenced via <img> tag

I was having the same issue with an SVG image included via the IMG tag. It turned out for me that Chrome didn't like there being a blank line directly at the top of the file.

I removed the blank line and my SVG immediately started rendering.

How to set the timezone in Django?

To get a set of all valid timezone names (ids) from the tz database, you could use pytz module in Python:

>>> import pytz # $ pip install pytz
>>> pytz.all_timezones_set

Convert row to column header for Pandas DataFrame,

It would be easier to recreate the data frame. This would also interpret the columns types from scratch.

headers = df.iloc[0]
new_df  = pd.DataFrame(df.values[1:], columns=headers)

how concatenate two variables in batch script?

The way is correct, but can be improved a bit with the extended set-syntax.

set "var=xyz"

Sets the var to the content until the last quotation mark, this ensures that no "hidden" spaces are appended.

Your code would look like

set "var1=A"
set "var2=B"
set "AB=hi"
set "newvar=%var1%%var2%"
echo %newvar% is the concat of var1 and var2
echo !%newvar%! is the indirect content of newvar

What does AngularJS do better than jQuery?


You go around making your webpage, and keep on putting {{data bindings}} whenever you feel you would have dynamic data. Angular will then provide you a $scope handler, which you can populate (statically or through calls to the web server).

This is a good understanding of data-binding. I think you've got that down.

DOM Manipulation

For simple DOM manipulation, which doesnot involve data manipulation (eg: color changes on mousehover, hiding/showing elements on click), jQuery or old-school js is sufficient and cleaner. This assumes that the model in angular's mvc is anything that reflects data on the page, and hence, css properties like color, display/hide, etc changes dont affect the model.

I can see your point here about "simple" DOM manipulation being cleaner, but only rarely and it would have to be really "simple". I think DOM manipulation is one the areas, just like data-binding, where Angular really shines. Understanding this will also help you see how Angular considers its views.

I'll start by comparing the Angular way with a vanilla js approach to DOM manipulation. Traditionally, we think of HTML as not "doing" anything and write it as such. So, inline js, like "onclick", etc are bad practice because they put the "doing" in the context of HTML, which doesn't "do". Angular flips that concept on its head. As you're writing your view, you think of HTML as being able to "do" lots of things. This capability is abstracted away in angular directives, but if they already exist or you have written them, you don't have to consider "how" it is done, you just use the power made available to you in this "augmented" HTML that angular allows you to use. This also means that ALL of your view logic is truly contained in the view, not in your javascript files. Again, the reasoning is that the directives written in your javascript files could be considered to be increasing the capability of HTML, so you let the DOM worry about manipulating itself (so to speak). I'll demonstrate with a simple example.

This is the markup we want to use. I gave it an intuitive name.

<div rotate-on-click="45"></div>

First, I'd just like to comment that if we've given our HTML this functionality via a custom Angular Directive, we're already done. That's a breath of fresh air. More on that in a moment.

Implementation with jQuery

live demo here (click).

function rotate(deg, elem) {
    webkitTransform: 'rotate('+deg+'deg)', 
    mozTransform: 'rotate('+deg+'deg)', 
    msTransform: 'rotate('+deg+'deg)', 
    oTransform: 'rotate('+deg+'deg)', 
    transform: 'rotate('+deg+'deg)'    

function addRotateOnClick($elems) {
  $elems.each(function(i, elem) {
    var deg = 0;
    $(elem).click(function() {
      deg+= parseInt($(this).attr('rotate-on-click'), 10);
      rotate(deg, this);


Implementation with Angular

live demo here (click).

app.directive('rotateOnClick', function() {
  return {
    restrict: 'A',
    link: function(scope, element, attrs) {
      var deg = 0;
      element.bind('click', function() {
        deg+= parseInt(attrs.rotateOnClick, 10);
          webkitTransform: 'rotate('+deg+'deg)', 
          mozTransform: 'rotate('+deg+'deg)', 
          msTransform: 'rotate('+deg+'deg)', 
          oTransform: 'rotate('+deg+'deg)', 
          transform: 'rotate('+deg+'deg)'    

Pretty light, VERY clean and that's just a simple manipulation! In my opinion, the angular approach wins in all regards, especially how the functionality is abstracted away and the dom manipulation is declared in the DOM. The functionality is hooked onto the element via an html attribute, so there is no need to query the DOM via a selector, and we've got two nice closures - one closure for the directive factory where variables are shared across all usages of the directive, and one closure for each usage of the directive in the link function (or compile function).

Two-way data binding and directives for DOM manipulation are only the start of what makes Angular awesome. Angular promotes all code being modular, reusable, and easily testable and also includes a single-page app routing system. It is important to note that jQuery is a library of commonly needed convenience/cross-browser methods, but Angular is a full featured framework for creating single page apps. The angular script actually includes its own "lite" version of jQuery so that some of the most essential methods are available. Therefore, you could argue that using Angular IS using jQuery (lightly), but Angular provides much more "magic" to help you in the process of creating apps.

This is a great post for more related information: How do I “think in AngularJS” if I have a jQuery background?

General differences.

The above points are aimed at the OP's specific concerns. I'll also give an overview of the other important differences. I suggest doing additional reading about each topic as well.

Angular and jQuery can't reasonably be compared.

Angular is a framework, jQuery is a library. Frameworks have their place and libraries have their place. However, there is no question that a good framework has more power in writing an application than a library. That's exactly the point of a framework. You're welcome to write your code in plain JS, or you can add in a library of common functions, or you can add a framework to drastically reduce the code you need to accomplish most things. Therefore, a more appropriate question is:

Why use a framework?

Good frameworks can help architect your code so that it is modular (therefore reusable), DRY, readable, performant and secure. jQuery is not a framework, so it doesn't help in these regards. We've all seen the typical walls of jQuery spaghetti code. This isn't jQuery's fault - it's the fault of developers that don't know how to architect code. However, if the devs did know how to architect code, they would end up writing some kind of minimal "framework" to provide the foundation (achitecture, etc) I discussed a moment ago, or they would add something in. For example, you might add RequireJS to act as part of your framework for writing good code.

Here are some things that modern frameworks are providing:

  • Templating
  • Data-binding
  • routing (single page app)
  • clean, modular, reusable architecture
  • security
  • additional functions/features for convenience

Before I further discuss Angular, I'd like to point out that Angular isn't the only one of its kind. Durandal, for example, is a framework built on top of jQuery, Knockout, and RequireJS. Again, jQuery cannot, by itself, provide what Knockout, RequireJS, and the whole framework built on top them can. It's just not comparable.

If you need to destroy a planet and you have a Death Star, use the Death star.

Angular (revisited).

Building on my previous points about what frameworks provide, I'd like to commend the way that Angular provides them and try to clarify why this is matter of factually superior to jQuery alone.

DOM reference.

In my above example, it is just absolutely unavoidable that jQuery has to hook onto the DOM in order to provide functionality. That means that the view (html) is concerned about functionality (because it is labeled with some kind of identifier - like "image slider") and JavaScript is concerned about providing that functionality. Angular eliminates that concept via abstraction. Properly written code with Angular means that the view is able to declare its own behavior. If I want to display a clock:



Yes, we need to go to JavaScript to make that mean something, but we're doing this in the opposite way of the jQuery approach. Our Angular directive (which is in it's own little world) has "augumented" the html and the html hooks the functionality into itself.

MVW Architecure / Modules / Dependency Injection

Angular gives you a straightforward way to structure your code. View things belong in the view (html), augmented view functionality belongs in directives, other logic (like ajax calls) and functions belong in services, and the connection of services and logic to the view belongs in controllers. There are some other angular components as well that help deal with configuration and modification of services, etc. Any functionality you create is automatically available anywhere you need it via the Injector subsystem which takes care of Dependency Injection throughout the application. When writing an application (module), I break it up into other reusable modules, each with their own reusable components, and then include them in the bigger project. Once you solve a problem with Angular, you've automatically solved it in a way that is useful and structured for reuse in the future and easily included in the next project. A HUGE bonus to all of this is that your code will be much easier to test.

It isn't easy to make things "work" in Angular.

THANK GOODNESS. The aforementioned jQuery spaghetti code resulted from a dev that made something "work" and then moved on. You can write bad Angular code, but it's much more difficult to do so, because Angular will fight you about it. This means that you have to take advantage (at least somewhat) to the clean architecture it provides. In other words, it's harder to write bad code with Angular, but more convenient to write clean code.

Angular is far from perfect. The web development world is always growing and changing and there are new and better ways being put forth to solve problems. Facebook's React and Flux, for example, have some great advantages over Angular, but come with their own drawbacks. Nothing's perfect, but Angular has been and is still awesome for now. Just as jQuery once helped the web world move forward, so has Angular, and so will many to come.

HTML tag inside JavaScript

This is what I used for my countdown clock:

<center class="auto-style19" style="height: 31px">
<Font face="blacksmith" size="large"><strong>
var header = "You have <I><font color=red>" 
+ getDaysUntilICD10() + "</font></I>&nbsp; "
header += "days until ICD-10 starts!"

The HTML inside of my script worked, though I could not explain why.

Best way to find if an item is in a JavaScript array?

If you are using jQuery:

$.inArray(5 + 5, [ "8", "9", "10", 10 + "" ]);

For more information:

What happened to console.log in IE8?

Even better for fallback is this:

   var alertFallback = true;
   if (typeof console === "undefined" || typeof console.log === "undefined") {
     console = {};
     if (alertFallback) {
         console.log = function(msg) {
     } else {
         console.log = function() {};

Determine device (iPhone, iPod Touch) with iOS

I'd like to add that to retrieve the front and enclosure color of the device there's a private API:

UIDevice *device = [UIDevice currentDevice];
SEL selector = NSSelectorFromString([device.systemVersion hasPrefix:@"7"] ? @"_deviceInfoForKey:" :  @"deviceInfoForKey:");
if ([device respondsToSelector:selector]) {
    NSLog(@"DeviceColor: %@ DeviceEnclosureColor: %@", [device performSelector:selector withObject:@"DeviceColor"], [device performSelector:selector withObject:@"DeviceEnclosureColor"]);

I've blogged about this and provide a sample app:

Resizing an Image without losing any quality

See if you like the image resizing quality of this open source ASP.NET module. There's a live demo, so you can mess around with it yourself. It yields results that are (to me) impossible to distinguish from Photoshop output. It also has similar file sizes - MS did a good job on their JPEG encoder.

What are the nuances of scope prototypal / prototypical inheritance in AngularJS?

Quick answer:
A child scope normally prototypically inherits from its parent scope, but not always. One exception to this rule is a directive with scope: { ... } -- this creates an "isolate" scope that does not prototypically inherit. This construct is often used when creating a "reusable component" directive.

As for the nuances, scope inheritance is normally straightfoward... until you need 2-way data binding (i.e., form elements, ng-model) in the child scope. Ng-repeat, ng-switch, and ng-include can trip you up if you try to bind to a primitive (e.g., number, string, boolean) in the parent scope from inside the child scope. It doesn't work the way most people expect it should work. The child scope gets its own property that hides/shadows the parent property of the same name. Your workarounds are

  1. define objects in the parent for your model, then reference a property of that object in the child: parentObj.someProp
  2. use $parent.parentScopeProperty (not always possible, but easier than 1. where possible)
  3. define a function on the parent scope, and call it from the child (not always possible)

New AngularJS developers often do not realize that ng-repeat, ng-switch, ng-view, ng-include and ng-if all create new child scopes, so the problem often shows up when these directives are involved. (See this example for a quick illustration of the problem.)

This issue with primitives can be easily avoided by following the "best practice" of always have a '.' in your ng-models – watch 3 minutes worth. Misko demonstrates the primitive binding issue with ng-switch.

Having a '.' in your models will ensure that prototypal inheritance is in play. So, use

<input type="text" ng-model="someObj.prop1">

<!--rather than
<input type="text" ng-model="prop1">`

L-o-n-g answer:

JavaScript Prototypal Inheritance

Also placed on the AngularJS wiki:

It is important to first have a solid understanding of prototypal inheritance, especially if you are coming from a server-side background and you are more familiar with class-ical inheritance. So let's review that first.

Suppose parentScope has properties aString, aNumber, anArray, anObject, and aFunction. If childScope prototypically inherits from parentScope, we have:

prototypal inheritance

(Note that to save space, I show the anArray object as a single blue object with its three values, rather than an single blue object with three separate gray literals.)

If we try to access a property defined on the parentScope from the child scope, JavaScript will first look in the child scope, not find the property, then look in the inherited scope, and find the property. (If it didn't find the property in the parentScope, it would continue up the prototype chain... all the way up to the root scope). So, these are all true:

childScope.aString === 'parent string'
childScope.anArray[1] === 20
childScope.anObject.property1 === 'parent prop1'
childScope.aFunction() === 'parent output'

Suppose we then do this:

childScope.aString = 'child string'

The prototype chain is not consulted, and a new aString property is added to the childScope. This new property hides/shadows the parentScope property with the same name. This will become very important when we discuss ng-repeat and ng-include below.

property hiding

Suppose we then do this:

childScope.anArray[1] = '22'
childScope.anObject.property1 = 'child prop1'

The prototype chain is consulted because the objects (anArray and anObject) are not found in the childScope. The objects are found in the parentScope, and the property values are updated on the original objects. No new properties are added to the childScope; no new objects are created. (Note that in JavaScript arrays and functions are also objects.)

follow the prototype chain

Suppose we then do this:

childScope.anArray = [100, 555]
childScope.anObject = { name: 'Mark', country: 'USA' }

The prototype chain is not consulted, and child scope gets two new object properties that hide/shadow the parentScope object properties with the same names.

more property hiding


  • If we read childScope.propertyX, and childScope has propertyX, then the prototype chain is not consulted.
  • If we set childScope.propertyX, the prototype chain is not consulted.

One last scenario:

delete childScope.anArray
childScope.anArray[1] === 22  // true

We deleted the childScope property first, then when we try to access the property again, the prototype chain is consulted.

after removing a child property

Angular Scope Inheritance

The contenders:

  • The following create new scopes, and inherit prototypically: ng-repeat, ng-include, ng-switch, ng-controller, directive with scope: true, directive with transclude: true.
  • The following creates a new scope which does not inherit prototypically: directive with scope: { ... }. This creates an "isolate" scope instead.

Note, by default, directives do not create new scope -- i.e., the default is scope: false.


Suppose we have in our controller:

$scope.myPrimitive = 50;
$scope.myObject    = {aNumber: 11};

And in our HTML:

<script type="text/ng-template" id="/tpl1.html">
<input ng-model="myPrimitive">
<div ng-include src="'/tpl1.html'"></div>

<script type="text/ng-template" id="/tpl2.html">
<input ng-model="myObject.aNumber">
<div ng-include src="'/tpl2.html'"></div>

Each ng-include generates a new child scope, which prototypically inherits from the parent scope.

ng-include child scopes

Typing (say, "77") into the first input textbox causes the child scope to get a new myPrimitive scope property that hides/shadows the parent scope property of the same name. This is probably not what you want/expect.

ng-include with a primitive

Typing (say, "99") into the second input textbox does not result in a new child property. Because tpl2.html binds the model to an object property, prototypal inheritance kicks in when the ngModel looks for object myObject -- it finds it in the parent scope.

ng-include with an object

We can rewrite the first template to use $parent, if we don't want to change our model from a primitive to an object:

<input ng-model="$parent.myPrimitive">

Typing (say, "22") into this input textbox does not result in a new child property. The model is now bound to a property of the parent scope (because $parent is a child scope property that references the parent scope).

ng-include with $parent

For all scopes (prototypal or not), Angular always tracks a parent-child relationship (i.e., a hierarchy), via scope properties $parent, $$childHead and $$childTail. I normally don't show these scope properties in the diagrams.

For scenarios where form elements are not involved, another solution is to define a function on the parent scope to modify the primitive. Then ensure the child always calls this function, which will be available to the child scope due to prototypal inheritance. E.g.,

// in the parent scope
$scope.setMyPrimitive = function(value) {
     $scope.myPrimitive = value;

Here is a sample fiddle that uses this "parent function" approach. (The fiddle was written as part of this answer:

See also and


ng-switch scope inheritance works just like ng-include. So if you need 2-way data binding to a primitive in the parent scope, use $parent, or change the model to be an object and then bind to a property of that object. This will avoid child scope hiding/shadowing of parent scope properties.

See also AngularJS, bind scope of a switch-case?


Ng-repeat works a little differently. Suppose we have in our controller:

$scope.myArrayOfPrimitives = [ 11, 22 ];
$scope.myArrayOfObjects    = [{num: 101}, {num: 202}]

And in our HTML:

<ul><li ng-repeat="num in myArrayOfPrimitives">
       <input ng-model="num">
<ul><li ng-repeat="obj in myArrayOfObjects">
       <input ng-model="obj.num">

For each item/iteration, ng-repeat creates a new scope, which prototypically inherits from the parent scope, but it also assigns the item's value to a new property on the new child scope. (The name of the new property is the loop variable's name.) Here's what the Angular source code for ng-repeat actually is:

childScope = scope.$new();  // child scope prototypically inherits from parent scope
childScope[valueIdent] = value;  // creates a new childScope property

If item is a primitive (as in myArrayOfPrimitives), essentially a copy of the value is assigned to the new child scope property. Changing the child scope property's value (i.e., using ng-model, hence child scope num) does not change the array the parent scope references. So in the first ng-repeat above, each child scope gets a num property that is independent of the myArrayOfPrimitives array:

ng-repeat with primitives

This ng-repeat will not work (like you want/expect it to). Typing into the textboxes changes the values in the gray boxes, which are only visible in the child scopes. What we want is for the inputs to affect the myArrayOfPrimitives array, not a child scope primitive property. To accomplish this, we need to change the model to be an array of objects.

So, if item is an object, a reference to the original object (not a copy) is assigned to the new child scope property. Changing the child scope property's value (i.e., using ng-model, hence obj.num) does change the object the parent scope references. So in the second ng-repeat above, we have:

ng-repeat with objects

(I colored one line gray just so that it is clear where it is going.)

This works as expected. Typing into the textboxes changes the values in the gray boxes, which are visible to both the child and parent scopes.

See also Difficulty with ng-model, ng-repeat, and inputs and


Nesting controllers using ng-controller results in normal prototypal inheritance, just like ng-include and ng-switch, so the same techniques apply. However, "it is considered bad form for two controllers to share information via $scope inheritance" -- A service should be used to share data between controllers instead.

(If you really want to share data via controllers scope inheritance, there is nothing you need to do. The child scope will have access to all of the parent scope properties. See also Controller load order differs when loading or navigating)


  1. default (scope: false) - the directive does not create a new scope, so there is no inheritance here. This is easy, but also dangerous because, e.g., a directive might think it is creating a new property on the scope, when in fact it is clobbering an existing property. This is not a good choice for writing directives that are intended as reusable components.
  2. scope: true - the directive creates a new child scope that prototypically inherits from the parent scope. If more than one directive (on the same DOM element) requests a new scope, only one new child scope is created. Since we have "normal" prototypal inheritance, this is like ng-include and ng-switch, so be wary of 2-way data binding to parent scope primitives, and child scope hiding/shadowing of parent scope properties.
  3. scope: { ... } - the directive creates a new isolate/isolated scope. It does not prototypically inherit. This is usually your best choice when creating reusable components, since the directive cannot accidentally read or modify the parent scope. However, such directives often need access to a few parent scope properties. The object hash is used to set up two-way binding (using '=') or one-way binding (using '@') between the parent scope and the isolate scope. There is also '&' to bind to parent scope expressions. So, these all create local scope properties that are derived from the parent scope. Note that attributes are used to help set up the binding -- you can't just reference parent scope property names in the object hash, you have to use an attribute. E.g., this won't work if you want to bind to parent property parentProp in the isolated scope: <div my-directive> and scope: { localProp: '@parentProp' }. An attribute must be used to specify each parent property that the directive wants to bind to: <div my-directive the-Parent-Prop=parentProp> and scope: { localProp: '@theParentProp' }.
    Isolate scope's __proto__ references Object. Isolate scope's $parent references the parent scope, so although it is isolated and doesn't inherit prototypically from the parent scope, it is still a child scope.
    For the picture below we have
    <my-directive interpolated="{{parentProp1}}" twowayBinding="parentProp2"> and
    scope: { interpolatedProp: '@interpolated', twowayBindingProp: '=twowayBinding' }
    Also, assume the directive does this in its linking function: scope.someIsolateProp = "I'm isolated"
    isolated scope
    For more information on isolate scopes see
  4. transclude: true - the directive creates a new "transcluded" child scope, which prototypically inherits from the parent scope. The transcluded and the isolated scope (if any) are siblings -- the $parent property of each scope references the same parent scope. When a transcluded and an isolate scope both exist, isolate scope property $$nextSibling will reference the transcluded scope. I'm not aware of any nuances with the transcluded scope.
    For the picture below, assume the same directive as above with this addition: transclude: true
    transcluded scope

This fiddle has a showScope() function that can be used to examine an isolate and transcluded scope. See the instructions in the comments in the fiddle.


There are four types of scopes:

  1. normal prototypal scope inheritance -- ng-include, ng-switch, ng-controller, directive with scope: true
  2. normal prototypal scope inheritance with a copy/assignment -- ng-repeat. Each iteration of ng-repeat creates a new child scope, and that new child scope always gets a new property.
  3. isolate scope -- directive with scope: {...}. This one is not prototypal, but '=', '@', and '&' provide a mechanism to access parent scope properties, via attributes.
  4. transcluded scope -- directive with transclude: true. This one is also normal prototypal scope inheritance, but it is also a sibling of any isolate scope.

For all scopes (prototypal or not), Angular always tracks a parent-child relationship (i.e., a hierarchy), via properties $parent and $$childHead and $$childTail.

Diagrams were generated with "*.dot" files, which are on github. Tim Caswell's "Learning JavaScript with Object Graphs" was the inspiration for using GraphViz for the diagrams.

What is the difference between pull and clone in git?

git clone <remote-url> <=>

  • create a new directory
  • git init // init new repository
  • git remote add origin <remote-url> // add remote
  • git fetch // fetch all remote branchs
  • git switch <default_branch> // switch to the default branch

git pull <=>

  • fetch ALL remote branches
  • merge CURRENT local branch with tracking remote branch (not another branch) (if local branch existed)

git pull <remote> <branch> <=>

  • fetch the remote branch
  • merge CURRENT local branch with the remote branch (if local branch existed)

Redirect using AngularJS

Don't forget to inject $location into controller.

Found conflicts between different versions of the same dependent assembly that could not be resolved

VS 2017, MVC project

I don't know why, but for me, the solution for this issue was to remove an out parameter from a model method signature that was called from the controller action method. that is very strange behaviour but that was the solution to my problem.

HTML Table cell background image alignment

This works in IE9 (Compatibility View and Normal Mode), Firefox 17, and Chrome 23:

        <td style="background-image:url(untitled.png); background-position:right 0px; background-repeat:no-repeat;">
            Hello World

You are trying to add a non-nullable field 'new_field' to userprofile without a default

If the SSH it gives you 2 options, choose number 1, and put "None". Just that...for the moment.

'Incorrect SET Options' Error When Building Database Project

In my case I was trying to create a table from one database to another on MS SQL Server 2012. Right-clicking on a table and selecting Script Table as > DROP And CREATE To > New Query Editor Window, following script was created:


ALTER TABLE [dbo].[Employees] DROP CONSTRAINT [FK_Employees_Departments]

/****** Object:  Table [dbo].[Employees]    Script Date: 8/24/2016 9:31:15 PM ******/
DROP TABLE [dbo].[Employees]

/****** Object:  Table [dbo].[Employees]    Script Date: 8/24/2016 9:31:15 PM ******/



CREATE TABLE [dbo].[Employees](
    [EmployeeId] [int] IDENTITY(1,1) NOT NULL,
    [DepartmentId] [int] NOT NULL,
    [FullName] [varchar](50) NOT NULL,
    [HireDate] [datetime] NULL
    [EmployeeId] ASC



ALTER TABLE [dbo].[Employees]  WITH CHECK ADD  CONSTRAINT [FK_Employees_Departments] FOREIGN KEY([DepartmentId])
REFERENCES [dbo].[Departments] ([DepartmentID])

ALTER TABLE [dbo].[Employees] CHECK CONSTRAINT [FK_Employees_Departments]

However when executing above script it was returning the error:

SELECT failed because the following SET options have incorrect settings: 'ANSI_PADDING'. Verify that SET options are correct for use with indexed views and/or indexes on computed columns and/or filtered indexes and/or query notifications and/or XML data type methods and/or spatial index operations.

The Solution I've found: Enabling the settings on the Top of the script like this:

/****** Object:  Table [dbo].[Employees]    Script Date: 8/24/2016 9:31:15 PM ******/



ALTER TABLE [dbo].[Employees] DROP CONSTRAINT [FK_Employees_Departments]

/****** Object:  Table [dbo].[Employees]    Script Date: 8/24/2016 9:31:15 PM ******/
DROP TABLE [dbo].[Employees]

CREATE TABLE [dbo].[Employees](
    [EmployeeId] [int] IDENTITY(1,1) NOT NULL,
    [DepartmentId] [int] NOT NULL,
    [FullName] [varchar](50) NOT NULL,
    [HireDate] [datetime] NULL
    [EmployeeId] ASC


ALTER TABLE [dbo].[Employees]  WITH CHECK ADD  CONSTRAINT [FK_Employees_Departments] FOREIGN KEY([DepartmentId])
REFERENCES [dbo].[Departments] ([DepartmentID])

ALTER TABLE [dbo].[Employees] CHECK CONSTRAINT [FK_Employees_Departments]


Hope this help.

How to delete columns in a CSV file?

you can use the csv package to iterate over your csv file and output the columns that you want to another csv file.

The example below is not tested and should illustrate a solution:

import csv

file_name = 'C:\Temp\my_file.csv'
output_file = 'C:\Temp\new_file.csv'
csv_file = open(file_name, 'r')
## note that the index of the year column is excluded
column_indices = [0,1,3,4]
with open(output_file, 'w') as fh:
    reader = csv.reader(csv_file, delimiter=',')
    for row in reader:
       tmp_row = []
       for col_inx in column_indices:

Modulo operation with negative numbers

I don't think there isn't any need to check if the number is negative.

A simple function to find the positive modulo would be this -

Edit: Assuming N > 0 and N + N - 1 <= INT_MAX

int modulo(int x,int N){
    return (x % N + N) %N;

This will work for both positive and negative values of x.

Original P.S: also as pointed out by @chux, If your x and N may reach something like INT_MAX-1 and INT_MAX respectively, just replace int with long long int.

And If they are crossing limits of long long as well (i.e. near LLONG_MAX), then you shall handle positive and negative cases separately as described in other answers here.

How to take character input in java

use :

char ch=**scanner.nextChar**()

How do I programmatically "restart" an Android app?

fun triggerRestart(context: Activity) {
    val intent = Intent(context,
    if (context is Activity) {
        (context as Activity).finish()

How to include *.so library in Android Studio?

*.so library in Android Studio

You have to generate jniLibs folder inside main in android Studio projects and put your all .so files inside. You can also integrate this line in build.gradle

compile fileTree(dir: 'libs', include: ['.jar','.so'])

It's work perfectly






|--|--|--|--|--| Files

This is the project structure.

Run-time error '1004' - Method 'Range' of object'_Global' failed


Range(DataImportColumn & DataImportRow).Offset(0, 2).Value



When you just have the row and the column then you can use the cells() object. The syntax is Cells(Row,Column)

Also one more tip. You might want to fully qualify your Cells object. for example


How to use Microsoft.Office.Interop.Excel on a machine without installed MS Office?

If the "Customer don't want to install and buy MS Office on a server not at any price", then you cannot use Excel ... But I cannot get the trick: it's all about one basic Office licence which costs something like 150 USD ... And I guess that spending time finding an alternative will cost by far more than this amount!

What is the difference between ArrayList.clear() and ArrayList.removeAll()?

The time complexity of ArrayList.clear() is O(n) and of removeAll is O(n^2).

So yes, ArrayList.clear is much faster.

How can I add a table of contents to a Jupyter / JupyterLab notebook?

JupyterLab ToC instructions

There are already many good answers to this question, but they often require tweaks to work properly with notebooks in JupyterLab. I wrote this answer to detail the possible ways of including a ToC in a notebook while working in and exporting from JupyterLab.

As a side panel

The jupyterlab-toc extension adds the ToC as a side panel that can number headings, collapse sections, and be used for navigation (see gif below for a demo). This extension is included by default since JupyterLab 3.0, in older version you can install it with the following command

jupyter labextension install @jupyterlab/toc

enter image description here

In the notebook as a cell

At the time being, this can either be done manually as in Matt Dancho's answer, or automatically via the toc2 jupyter notebook extension in the classic notebook interface.

First, install toc2 as part of the jupyter_contrib_nbextensions bundle:

conda install -c conda-forge jupyter_contrib_nbextensions

Then, launch JupyterLab, go to Help --> Launch Classic Notebook, and open the notebook in which you want to add the ToC. Click the toc2 symbol in the toolbar to bring up the floating ToC window (see the gif below if you can't find it), click the gear icon and check the box for "Add notebook ToC cell". Save the notebook and the ToC cell will be there when you open it in JupyterLab. The inserted cell is a markdown cell with html in it, it will not update automatically.

The default options of the toc2 can be configured in the "Nbextensions" tab in the classic notebook launch page. You can e.g. choose to number headings and to anchor the ToC as a side bar (which I personally think looks cleaner).

enter image description here

In an exported HTML file

nbconvert can be used to export notebooks to HTML following rules of how to format the exported HTML. The toc2 extension mentioned above adds an export format called html_toc, which can be used directly with nbconvert from the command line (after the toc2 extension has been installed):

jupyter nbconvert file.ipynb --to html_toc
# Append `--ExtractOutputPreprocessor.enabled=False`
# to get a single html file instead of a separate directory for images

Remember that shell commands can be added to notebook cells by prefacing them with an exclamation mark !, so you can stick this line in the last cell of the notebook and always have an HTML file with a ToC generated when you hit "Run all cells" (or whatever output you desire from nbconvert). This way, you could use jupyterlab-toc to navigate the notebook while you are working, and still get ToCs in the exported output without having to resort to using the classic notebook interface (for the purists among us).

Note that configuring the default toc2 options as described above, will not change the format of nbconver --to html_toc. You need to open the notebook in the classic notebook interface for the metadata to be written to the .ipynb file (nbconvert reads the metadata when exporting) Alternatively, you can add the metadata manually via the Notebook tools tab of the JupyterLab sidebar, e.g. something like:

    "toc": {
        "number_sections": false,
        "sideBar": true

If you prefer a GUI-driven approach, you should be able to open the classic notebook and click File --> Save as HTML (with ToC) (although note that this menu item was not available for me).

The gifs above are linked from the respective documentation of the extensions.

How can I move HEAD back to a previous location? (Detached head) & Undo commits

Before answering, let's add some background, explaining what this HEAD is.

First of all what is HEAD?

HEAD is simply a reference to the current commit (latest) on the current branch.
There can only be a single HEAD at any given time (excluding git worktree).

The content of HEAD is stored inside .git/HEAD and it contains the 40 bytes SHA-1 of the current commit.

detached HEAD

If you are not on the latest commit - meaning that HEAD is pointing to a prior commit in history it's called detached HEAD.

Enter image description here

On the command line, it will look like this - SHA-1 instead of the branch name since the HEAD is not pointing to the tip of the current branch:

Enter image description here

Enter image description here

A few options on how to recover from a detached HEAD:

git checkout

git checkout <commit_id>
git checkout -b <new branch> <commit_id>
git checkout HEAD~X // x is the number of commits to go back

This will checkout new branch pointing to the desired commit.
This command will checkout to a given commit.
At this point, you can create a branch and start to work from this point on.

# Checkout a given commit.
# Doing so will result in a `detached HEAD` which mean that the `HEAD`
# is not pointing to the latest so you will need to checkout branch
# in order to be able to update the code.
git checkout <commit-id>

# Create a new branch forked to the given commit
git checkout -b <branch name>

git reflog

You can always use the reflog as well.
git reflog will display any change which updated the HEAD and checking out the desired reflog entry will set the HEAD back to this commit.

Every time the HEAD is modified there will be a new entry in the reflog

git reflog
git checkout HEAD@{...}

This will get you back to your desired commit

Enter image description here

git reset --hard <commit_id>

"Move" your HEAD back to the desired commit.

# This will destroy any local modifications.
# Don't do it if you have uncommitted work you want to keep.
git reset --hard 0d1d7fc32

# Alternatively, if there's work to keep:
git stash
git reset --hard 0d1d7fc32
git stash pop
# This saves the modifications, then reapplies that patch after resetting.
# You could get merge conflicts if you've modified things which were
# changed since the commit you reset to.
  • Note: (Since Git 2.7) you can also use the git rebase --no-autostash as well.

git revert <sha-1>

"Undo" the given commit or commit range.
The reset command will "undo" any changes made in the given commit.
A new commit with the undo patch will be committed while the original commit will remain in the history as well.

# Add a new commit with the undo of the original one.
# The <sha-1> can be any commit(s) or commit range
git revert <sha-1>

This schema illustrates which command does what.
As you can see there, reset && checkout modify the HEAD.

Enter image description here

CSS selector (id contains part of text)

Try this:


This will get you all a elements with id containing


and have the id ending in


"Unknown class <MyClass> in Interface Builder file" error at runtime

In my case I had deleted a class called "viewController" not realising it was selected with the storyboard's identity inspector (under 'Custom Class' up the top).

You just have to simply select the correct class for the view controller in your identity inspector's Custom Class field or add a new class to your project and select that one as your Custom Class.

Worked for me!

What is .Net Framework 4 extended?

Got this from Bing. Seems Microsoft has removed some features from the core framework and added it to a separate optional(?) framework component.

To quote from MSDN (

The .NET Framework 4 Client Profile does not include the following features. You must install the .NET Framework 4 to use these features in your application:

* Advanced Windows Communication Foundation (WCF) functionality
* .NET Framework Data Provider for Oracle
* MSBuild for compiling

Error 500: Premature end of script headers

Check your line endings! If you see an error about the file not being found, followed by this "premature of end headers" error in your Apache log - it may be that you have Windows line endings in your script in instead of Unix style. I ran into that problem / solution.

use std::fill to populate vector with increasing numbers

I've seen the answers with std::generate but you can also "improve" that by using static variables inside the lambda, instead of declaring a counter outside of the function or creating a generator class :

std::vector<int> vec;
std::generate(vec.begin(), vec.end(), [] {
    static int i = 0;
    return i++;

I find it a little more concise

Can Mockito stub a method without regard to the argument?

anyObject() should fit your needs.

Also, you can always consider implementing hashCode() and equals() for the Bazoo class. This would make your code example work the way you want.

Passing capturing lambda as function pointer

A shortcut for using a lambda with as a C function pointer is this:

"auto fun = +[](){}"

Using Curl as exmample (curl debug info)

auto callback = +[](CURL* handle, curl_infotype type, char* data, size_t size, void*){ //add code here :-) };
curl_easy_setopt(curlHande, CURLOPT_VERBOSE, 1L);

How can I create a Java method that accepts a variable number of arguments?

Take a look at the Java guide on varargs.

You can create a method as shown below. Simply call System.out.printf instead of System.out.println(String.format(....

public static void print(String format, Object... args) {
    System.out.printf(format, args);

Alternatively, you can just use a static import if you want to type as little as possible. Then you don't have to create your own method:

import static java.lang.System.out;

out.printf("Numer of apples: %d", 10);

isset PHP isset($_GET['something']) ? $_GET['something'] : ''

You have encountered the ternary operator. It's purpose is that of a basic if-else statement. The following pieces of code do the same thing.


$something = isset($_GET['something']) ? $_GET['something'] : "failed";


if (isset($_GET['something'])) {
    $something = $_GET['something'];
} else {
    $something = "failed";

How do I download a binary file over HTTP?

if you looking for a way how to download temporary file, do stuff and delete it try this gem

require 'pull_tempfile'

PullTempfile.transaction(url: '', original_filename: 'dont-care.csv') do |tmp_file|
  CSV.foreach(tmp_file.path) do |row|
    # ....

How to convert string to boolean in typescript Angular 4

In your scenario, converting a string to a boolean can be done via something like someString === 'true' (as was already answered).

However, let me try to address your main issue: dealing with the local storage.

The local storage only supports strings as values; a good way of using it would thus be to always serialise your data as a string before storing it in the storage, and reversing the process when fetching it.

A possibly decent format for serialising your data in is JSON, since it is very easy to deal with in JavaScript.

The following functions could thus be used to interact with local storage, provided that your data can be serialised into JSON.

function setItemInStorage(key, item) {
  localStorage.setItem(key, JSON.stringify(item));

function getItemFromStorage(key) {
  return JSON.parse(localStorage.getItem(key));

Your example could then be rewritten as:

setItemInStorage('CheckOutPageReload', [this.btnLoginNumOne, this.btnLoginEdit]);


if (getItemFromStorage('CheckOutPageReload')) {
  const pageLoadParams = getItemFromStorage('CheckOutPageReload');
  this.btnLoginNumOne = pageLoadParams[0];
  this.btnLoginEdit = pageLoadParams[1];

Convert txt to csv python script

I suposse this is the output you need:



It can be done with this changes to your code:

import csv
import itertools

with open('log.txt', 'r') as in_file:
    lines =
    stripped = [line.replace(","," ").split() for line in lines]
    grouped = itertools.izip(*[stripped]*1)
    with open('log.csv', 'w') as out_file:
        writer = csv.writer(out_file)
        writer.writerow(('title', 'intro', 'tagline'))
        for group in grouped:

angularjs directive call function specified in attribute and pass an argument to it

This should work.

<div my-method='theMethodToBeCalled'></div>

app.directive("myMethod",function($parse) {
  scope: {theMethodToBeCalled: "="}
  link:function(scope,element,attrs) {
     $(element).on('theEvent',function( e, rowid ) {
        id = // some function called to determine id based on rowid

app.controller("myController",function($scope) {
   $scope.theMethodToBeCalled = function(id) { alert(id); };

How to pass arguments to a Button command in Tkinter?

Use lambda

import tkinter as tk

root = tk.Tk()
def go(text):

b = tk.Button(root, text="Click", command=lambda: go("hello"))



How to configure XAMPP to send mail from localhost?

I tried many ways to send a mail from XAMPP Localhost, but since XAMPP hasn't SSL Certificate, my email request blocked by Gmail or similar SMTP Service providers.

Then I used MailHog for local smtp server, what you need to do is just run it. localhost:1025 is for smtp server, localhost:8025 is for mail server, where you can check the emails you sent.

here is my code:

    require_once "src/PHPMailer.php";
    require_once "src/SMTP.php";
    require_once "src/Exception.php";

    $mail = new PHPMailer\PHPMailer\PHPMailer();

      //Server settings
    $mail->SMTPDebug = 3;                      // Enable verbose debug output
    $mail->isSMTP();                                            // Send using SMTP
    $mail->Host       = 'localhost';                    // Set the SMTP server to send through
    $mail->Port       = 1025;                                    // TCP port to connect to
    // $mail->Username   = '';                     // SMTP username
    // $mail->Password   = '';                               // SMTP password
    // $mail->SMTPAuth   = true;                                   // Enable SMTP authentication
    // $mail->SMTPSecure = 'tls';         // Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` also accepted

    $mail->setFrom('[email protected]', 'Mailer');
    $mail->addAddress('[email protected]', 'Joe User');     // Add a recipient

    // Content
    $mail->isHTML(true);                                  // Set email format to HTML
    $mail->Subject = 'Here is the subject';
    $mail->Body    = 'This is the HTML message body <b>in bold!</b>';
    $mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

    if(!$mail->Send()) {
        echo "Mailer Error: " . $mail->ErrorInfo;
    } else {
        echo "Message sent!";

MailHog Github Repository link

How to take column-slices of dataframe in pandas

Note: .ix has been deprecated since Pandas v0.20. You should instead use .loc or .iloc, as appropriate.

The DataFrame.ix index is what you want to be accessing. It's a little confusing (I agree that Pandas indexing is perplexing at times!), but the following seems to do what you want:

>>> df = DataFrame(np.random.rand(4,5), columns = list('abcde'))
>>> df.ix[:,'b':]
      b         c         d         e
0  0.418762  0.042369  0.869203  0.972314
1  0.991058  0.510228  0.594784  0.534366
2  0.407472  0.259811  0.396664  0.894202
3  0.726168  0.139531  0.324932  0.906575

where .ix[row slice, column slice] is what is being interpreted. More on Pandas indexing here:

What is the meaning of single and double underscore before an object name?

Single leading underscores is a convention. there is no difference from the interpreter's point of view if whether names starts with a single underscore or not.

Double leading and trailing underscores are used for built-in methods, such as __init__, __bool__, etc.

Double leading underscores w/o trailing counterparts are a convention too, however, the class methods will be mangled by the interpreter. For variables or basic function names no difference exists.

C - Convert an uppercase letter to lowercase

#include <stdio.h>
#include <string.h>

int main()
    char string[] = "Strlwr in C";


    return  0;

use strlwr for lowering the case

Select all 'tr' except the first one

ideal solution but not supported in IE

tr:not(:first-child) {css}

second solution would be to style all tr's and then override with css for first-child:

tr {css}
tr:first-child {override css above}

How to extract HTTP response body from a Python requests call?

Your code is correct. I tested:

r = requests.get("")

And it returned plenty of content. Check the url, try "". Cheers!

How do I put my website's logo to be the icon image in browser tabs?

That image is called 'favicon' and it's a small square shaped .ico file, which is the standard file type for favicons. You could use .png or .gif too, but you should follow the standard for better compatibility.

To set one for your website you should:

  1. Make a square image of your logo (preferably 32x32 or 16x16 pixels, as far as I know there's no max size*), and transform it into an .ico file. You can do this on Gimp, Photoshop (with help of a plugin) or a website like or RealFaviconGenerator.

  2. Then, you have two ways of setting it up:

    A) Placing it on the root folder/directory of your website (next to index.html) with the name favicon.ico.


    B) Link to it between the <head></head> tags of every .html file on your site, like this:

      <link rel="shortcut icon" type="image/x-icon" href="favicon.ico" />

If you want to see the favicon from any website, just write and you'll (probably) see it. Stackoverflow's favicon is 16x16 pixels and Wikipedia is 32x32.

*: There's even a browser problem with no filesize limit. You could easily crash a browser with an exceedingly large favicon, more info here

How to represent multiple conditions in a shell if statement?

In bash for string comparison, you can use the following technique.

if [ $var OP "val" ]; then
    echo "statements"


if [ $var != "otherthing" ] && [ $var != "everything" ] && [ $var != "allthings" ]; then
    echo "this will be printed"
    echo "this will not be printed"

Writing numerical values on the plot with Matplotlib

You can use the annotate command to place text annotations at any x and y values you want. To place them exactly at the data points you could do this

import numpy
from matplotlib import pyplot

x = numpy.arange(10)
y = numpy.array([5,3,4,2,7,5,4,6,3,2])

fig = pyplot.figure()
ax = fig.add_subplot(111)
for i,j in zip(x,y):

If you want the annotations offset a little, you could change the annotate line to something like


How do I get the current time zone of MySQL?

My PHP framework uses

SET LOCAL time_zone='Whatever'

on after connect, where 'Whatever' == date_default_timezone_get()

Not my solution, but this ensures SYSTEM timezone of MySQL server is always the same as PHP's one

So, yes, PHP is strongly envolved and can affect it

Show dialog from fragment?

I am a beginner myself and I honestly couldn't find a satisfactory answer that I could understand or implement.

So here's an external link that I really helped me achieved what I wanted. It's very straight forward and easy to follow as well.


I have a MainActivity that hosts a Fragment. I wanted a dialog to appear on top of the layout to ask for user input and then process the input accordingly. See a screenshot

Here's what the onCreateView of my fragment looks

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_home_activity, container, false);

    Button addTransactionBtn = rootView.findViewById(;

    addTransactionBtn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Dialog dialog = new Dialog(getActivity());
            dialog.setTitle("Add an Expense");



I hope it will help you

Let me know if there's any confusion. :)

How to automatically start a service when running a docker container?

This not works CMD service mysql start && /bin/bash

This not works CMD service mysql start ; /bin/bash ;

-- i guess interactive mode would not support foreground.

This works !! CMD service nginx start ; while true ; do sleep 100; done;

This works !! CMD service nginx start && tail -F /var/log/nginx/access.log

beware you should using docker run -p 80:80 nginx_bash without command parameter.

jQuery - keydown / keypress /keyup ENTERKEY detection?


    var code = e.key; // recommended to use e.key, it's normalized across devices and languages
    if(code==="Enter") e.preventDefault();
    if(code===" " || code==="Enter" || code===","|| code===";"){
    } // missing closing if brace


<input id="entersomething" type="text" /> <!-- put a type attribute in -->
<div id="displaysomething"></div>

Local and global temporary tables in SQL Server

It is worth mentioning that there is also: database scoped global temporary tables(currently supported only by Azure SQL Database).

Global temporary tables for SQL Server (initiated with ## table name) are stored in tempdb and shared among all users’ sessions across the whole SQL Server instance.

Azure SQL Database supports global temporary tables that are also stored in tempdb and scoped to the database level. This means that global temporary tables are shared for all users’ sessions within the same Azure SQL Database. User sessions from other databases cannot access global temporary tables.

-- Session A creates a global temp table ##test in Azure SQL Database testdb1
-- and adds 1 row
CREATE TABLE ##test ( a int, b int);
INSERT INTO ##test values (1,1);

-- Session B connects to Azure SQL Database testdb1 
-- and can access table ##test created by session A
SELECT * FROM ##test

-- Session C connects to another database in Azure SQL Database testdb2 
-- and wants to access ##test created in testdb1.
-- This select fails due to the database scope for the global temp tables 
SELECT * FROM ##test
Msg 208, Level 16, State 0, Line 1
Invalid object name '##test'



APPLIES TO: Azure SQL Database (feature is in public preview)

Allows setting the auto-drop functionality for global temporary tables. The default is ON, which means that the global temporary tables are automatically dropped when not in use by any session. When set to OFF, global temporary tables need to be explicitly dropped using a DROP TABLE statement or will be automatically dropped on server restart.

With Azure SQL Database single databases and elastic pools, this option can be set in the individual user databases of the SQL Database server. In SQL Server and Azure SQL Database managed instance, this option is set in TempDB and the setting of the individual user databases has no effect.

How to find/identify large commits in git history?

A blazingly fast shell one-liner

This shell script displays all blob objects in the repository, sorted from smallest to largest.

For my sample repo, it ran about 100 times faster than the other ones found here.
On my trusty Athlon II X4 system, it handles the Linux Kernel repository with its 5.6 million objects in just over a minute.

The Base Script

git rev-list --objects --all |
  git cat-file --batch-check='%(objecttype) %(objectname) %(objectsize) %(rest)' |
  sed -n 's/^blob //p' |
  sort --numeric-sort --key=2 |
  cut -c 1-12,41- |
  $(command -v gnumfmt || echo numfmt) --field=2 --to=iec-i --suffix=B --padding=7 --round=nearest

When you run above code, you will get nice human-readable output like this:

0d99bb931299  530KiB path/to/some-image.jpg
2ba44098e28f   12MiB path/to/hires-image.png
bd1741ddce0d   63MiB path/to/some-video-1080p.mp4

macOS users: Since numfmt is not available on macOS, you can either omit the last line and deal with raw byte sizes or brew install coreutils.


To achieve further filtering, insert any of the following lines before the sort line.

To exclude files that are present in HEAD, insert the following line:

grep -vF --file=<(git ls-tree -r HEAD | awk '{print $3}') |

To show only files exceeding given size (e.g. 1 MiB = 220 B), insert the following line:

awk '$2 >= 2^20' |

Output for Computers

To generate output that's more suitable for further processing by computers, omit the last two lines of the base script. They do all the formatting. This will leave you with something like this:

0d99bb93129939b72069df14af0d0dbda7eb6dba 542455 path/to/some-image.jpg
2ba44098e28f8f66bac5e21210c2774085d2319b 12446815 path/to/hires-image.png
bd1741ddce0d07b72ccf69ed281e09bf8a2d0b2f 65183843 path/to/some-video-1080p.mp4

File Removal

For the actual file removal, check out this SO question on the topic.

Put search icon near textbox using bootstrap

You can do it in pure CSS using the :after pseudo-element and getting creative with the margins.

Here's an example, using Font Awesome for the search icon:

.search-box-container input {_x000D_
  padding: 5px 20px 5px 5px;_x000D_
.search-box-container:after {_x000D_
    content: "\f002";_x000D_
    font-family: FontAwesome;_x000D_
    margin-left: -25px;_x000D_
    margin-right: 25px;_x000D_
<!-- font awesome -->_x000D_
<link href="" rel="stylesheet"/>_x000D_
<div class="search-box-container">_x000D_
  <input type="text" placeholder="Search..."  />_x000D_

How to downgrade php from 5.5 to 5.3

It is possible! Yes

In many cases, you might want to use XAMPP with a different PHP version than the one that comes preinstalled. You might do this to get the benefits of a newer version of PHP, or to reproduce bugs using an earlier version of PHP.

To use a different version of PHP with XAMPP, follow these steps:

  1. Download a binary build of the PHP version that you wish to use from the PHP website, and extract the contents of the compressed archive file to your XAMPP installation directory (usually, C:\xampp). Ensure that you give it a different directory name to avoid overwriting the existing PHP version. For example, in this tutorial, we’ll call the new directory C:\xampp\php5-6-0. NOTE : Ensure that the PHP build you download matches the Apache build (VC9 or VC11) in your XAMPP platform.

  2. Within the new directory, rename the php.ini-development file to php.ini. If you prefer to use production settings, you could instead rename the php.ini-production file to php.ini.

  3. Edit the httpd-xampp.conf file in the apache\conf\extra\ subdirectory of your XAMPP installation directory. Within this file, search for all instances of the old PHP directory path and replace them with the path to the new PHP directory created in Step 1. In particular, be sure to change the lines

    LoadFile "/xampp/php/php5ts.dll"
    LoadFile "/xampp/php/libpq.dll"
    LoadModule php5_module "/xampp/php/php5apache2_4.dll"


    LoadFile "/xampp/php5-6-0/php5ts.dll"
    LoadFile "/xampp/php5-6-0/libpq.dll"
    LoadModule php5_module "/xampp/php5-6-0/php5apache2_4.dll"

NOTE : Remember to adjust the file and directory paths above to reflect valid paths on your system.

  1. Restart your Apache server through the XAMPP control panel for your changes to take effect. The new version of PHP should now be active. To verify this, browse to the URL http://localhost/xampp/phpinfo.php, which displays the output of the phpinfo() command, and check the version number at the top of the page.

How do I change the owner of a SQL Server database?

to change the object owner try the following

EXEC sp_changedbowner 'sa'

that however is not your problem, to see diagrams the Da Vinci Tools objects have to be created (you will see tables and procs that start with dt_) after that

Set the Value of a Hidden field using JQuery

Drop the hash - that's for identifying the id attribute.

What is the difference between hg forget and hg remove?

A file can be tracked or not, you use hg add to track a file and hg remove or hg forget to un-track it. Using hg remove without flags will both delete the file and un-track it, hg forget will simply un-track it without deleting it.

C pass int array pointer as parameter into a function

In the function declaration you have to type as

void fun(int *a[])
//in the function body we can use as

How to hide columns in an ASP.NET GridView with auto-generated columns?

I found Steve Hibbert's response to be very helpful. The problem the OP seemed to be describing is that of an AutoGeneratedColumns on a GridView.

In this instance you can set which columns will be "visible" and which will be hidden when you bind a data table in the code behind.

For example: A Gridview is on the page as follows.

<asp:GridView ID="gv" runat="server" AutoGenerateColumns="False" >

And then in the code behind a PopulateGridView routine is called during the page load event.

protected void PopulateGridView()
    DataTable dt = GetDataSource();
    gv.DataSource = dt;
    foreach (DataColumn col in dt.Columns)
        BoundField field = new BoundField();
        field.DataField = col.ColumnName;
        field.HeaderText = col.ColumnName;
        if (col.ColumnName.EndsWith("ID"))
            field.Visible = false;

In the above the GridView AutoGenerateColumns is set to False and the codebehind is used to create the bound fields. One is obtaining the datasource as a datatable through one's own process which here I labeled GetDataSource(). Then one loops through the columns collection of the datatable. If the column name meets a given criteria, you can set the bound field visible property accordingly. Then you bind the data to the gridview. This is very similar to AutoGenerateColumns="True" but you get to have criteria for the columns. This approach is most useful when the criteria for hiding and un-hiding is based upon the column name.

Removing character in list of strings

A faster way is to join the list, replace 8 and split the new string:

mylist = [("aaaa8"),("bb8"),("ccc8"),("dddddd8")]
mylist = ' '.join(mylist).replace('8','').split()
print mylist

Are the PUT, DELETE, HEAD, etc methods available in most web browsers?

YES, PUT, DELETE, HEAD etc HTTP methods are available in all modern browsers.

To be compliant with XMLHttpRequest Level 2 browsers must support these methods. To check which browsers support XMLHttpRequest Level 2 I recommend CanIUse:

Only Opera Mini is lacking support atm (juli '15), but Opera Mini lacks support for everything. :)

jQuery get the image src

You may find likr


Numpy isnan() fails on an array of floats (from pandas dataframe apply)

A great substitute for np.isnan() and pd.isnull() is

for i in range(0,a.shape[0]):
       //do something here
       //a[i] is nan

since only nan is not equal to itself.

Find and Replace string in all files recursive using grep and sed

grep -rl $oldstring . | xargs sed -i "s/$oldstring/$newstring/g"

HTML select dropdown list

If you want to achieve the same for the jquery-ui selectmenu control then you have to set 'display: none' in the open event handler and add '-menu' to the id string.

<select id="myid">
<option value="" disabled="disabled" selected="selected">Please select     name</option>
 <option value="Tom">Tom</option>
 <option value="Marry">Mary</option>
 <option value="Jane">Jane</option>
 <option value="Harry">Harry</option>

  change: function( event, data ) {
open: function( event, ui ) {
    $('ul#myid-menu li:first-child').css('display', 'none');

Original purpose of <input type="hidden">?

basically hidden fields will be more useful and advantages to use with multi step form. we can use hidden fields to pass one step information to next step using hidden and keep it forwarding till the end step.

  1. CSRF tokens.

Cross-site request forgery is a very common website vulnerability. Requiring a secret, user-specific token in all form submissions will prevent CSRF attacks since attack sites cannot guess what the proper token is and any form submissions they perform on the behalf of the user will always fail.

  1. Save state in multi-page forms.

If you need to store what step in a multi-page form the user is currently on, use hidden input fields. The user doesn't need to see this information, so hide it in a hidden input field.

General rule: Use the field to store anything that the user doesn't need to see, but that you want to send to the server on form submission.

How to save data in an android app

use this methods to use sharedPreferences very easily.

private val sharedPreferences = context.getSharedPreferences("myPreferences", Context.MODE_PRIVATE)

fun put(key: String, value: String) = sharedPreferences.edit().putString(key, value).apply()

fun put(key: String, value: Int) = sharedPreferences.edit().putInt(key, value).apply()

fun put(key: String, value: Float) = sharedPreferences.edit().putFloat(key, value).apply()

fun put(key: String, value: Boolean) = sharedPreferences.edit().putBoolean(key, value).apply()

fun put(key: String, value: Long) = sharedPreferences.edit().putLong(key, value).apply()

fun getString(key: String, defaultValue: String? = null): String? = sharedPreferences.getString(key, defaultValue)

fun getInt(key: String, defaultValue: Int = -1): Int = sharedPreferences.getInt(key, defaultValue)

fun getFloat(key: String, defaultValue: Float = -1F): Float = sharedPreferences.getFloat(key, defaultValue)

fun getBoolean(key: String, defaultValue: Boolean = false): Boolean = sharedPreferences.getBoolean(key, defaultValue)

fun getLong(key: String, defaultValue: Long = -1L): Long = sharedPreferences.getLong(key, defaultValue)

fun clearAll() = sharedPreferences.edit().clear().apply()

put them in a class and get context in its constructor.

Is 'bool' a basic datatype in C++?

yes, it was introduced in 1993.

for further reference: Boolean Datatype

console.writeline and System.out.println

First I am afraid your question contains a little mistake. There is not method writeline in class Console. Instead class Console provides method writer() that returns PrintWriter. This print writer has println().

Now what is the difference between

System.console().writer().println("hello from console");


System.out.println("hello system out");

If you run your application from command line I think there is no difference. But if console is unavailable System.console() returns null while System.out still exists. This may happen if you invoke your application and perform redirect of STDOUT to file.

Here is an example I have just implemented.


public class TestConsole {
    public static void main(String[] args) {
        Console console = System.console();
        System.out.println("console=" + console);
        console.writer().println("hello from console");

When I ran the application from command prompt I got the following:

$ java TestConsole
hello from console

but when I redirected the STDOUT to file...

$ java TestConsole >/tmp/test
Exception in thread "main" java.lang.NullPointerException
        at TestConsole.main(

Line 8 is console.writer().println().

Here is the content of /tmp/test


I hope my explanations help.

How to enable GZIP compression in IIS 7.5

GZip Compression can be enabled directly through IIS.

First, open up IIS,

go to the website you are hoping to tweak and hit the Compression page. If Gzip is not installed, you will see something like the following:


“The dynamic content compression module is not installed.” We should fix this. So we go to the “Turn Windows features on or off” and select “Dynamic Content Compression” and click the OK button.

Now if we go back to IIS, we should see that the compression page has changed. At this point we need to make sure the dynamic compression checkbox is checked and we’re good to go. Compression is enabled and our dynamic content will be Gzipped.

Testing - Check if GZIP Compression is Enabled

To test whether compression is working or not, use the developer tools in Chrome or Firebug for Firefox and ensure the HTTP response header is set:

Content-Encoding: gzip

PHP - Get key name of array value

If i understand correctly, can't you simply use:

foreach($arr as $key=>$value)
  echo $key;

See PHP manual

How to execute shell command in Javascript

Another post on this topic with a nice jQuery/Ajax/PHP solution:

shell scripting and jQuery

Command copy exited with code 4 when building - Visual Studio restart solves it

Run VS in Administrator mode and it should work fine.

How do I center list items inside a UL element?

I have run into this issue before and found that sometimes padding is the issue.

By removing padding from the ul, any li's set to inline-block will be nicely centred:

* {_x000D_
 box-sizing: border-box;_x000D_
ul {_x000D_
 width: 120px;_x000D_
 margin: auto;_x000D_
 text-align: center;_x000D_
 border: 1px solid black;_x000D_
li {_x000D_
 display: inline-block;_x000D_
ul.no_pad {_x000D_
 padding: 0;_x000D_
p {_x000D_
 margin: auto;_x000D_
 text-align: center;_x000D_
.break {_x000D_
 margin: 50px 10px;_x000D_
<div>  _x000D_
  <p>With Padding (Default Style)</p>_x000D_
            <ul class="with_pad">_x000D_
  <div class="break"></div>_x000D_
  <p>No Padding (Padding: 0)</p>_x000D_
   <ul class="no_pad">_x000D_

Hope that helps anyone running into this same issue :)



You cannot call a method on a null-valued expression

The simple answer for this one is that you have an undeclared (null) variable. In this case it is $md5. From the comment you put this needed to be declared elsewhere in your code

$md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider

The error was because you are trying to execute a method that does not exist.

PS C:\Users\Matt> $md5 | gm

   TypeName: System.Security.Cryptography.MD5CryptoServiceProvider

Name                       MemberType Definition                                                                                                                            
----                       ---------- ----------                                                                                                                            
Clear                      Method     void Clear()                                                                                                                          
ComputeHash                Method     byte[] ComputeHash(System.IO.Stream inputStream), byte[] ComputeHash(byte[] buffer), byte[] ComputeHash(byte[] buffer, int offset, ...

The .ComputeHash() of $md5.ComputeHash() was the null valued expression. Typing in gibberish would create the same effect.

PS C:\Users\Matt> $bagel.MakeMeABagel()
You cannot call a method on a null-valued expression.
At line:1 char:1
+ $bagel.MakeMeABagel()
+ ~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

PowerShell by default allows this to happen as defined its StrictMode

When Set-StrictMode is off, uninitialized variables (Version 1) are assumed to have a value of 0 (zero) or $Null, depending on type. References to non-existent properties return $Null, and the results of function syntax that is not valid vary with the error. Unnamed variables are not permitted.

PHP Warning: Module already loaded in Unknown on line 0

In Windows 10, I fix this by comment like this


Combine several images horizontally with Python

merge_image takes three parameters first two parameters specify 
the two images to be merged and third parameter i.e. vertically
is a boolean type which if True merges images vertically
and finally saves and returns the file_name
def merge_image(img1, img2, vertically):
    images = list(map(, [img1, img2]))
    widths, heights = zip(*(i.size for i in images))
    if vertically:
        max_width = max(widths)
        total_height = sum(heights)
        new_im ='RGB', (max_width, total_height))

        y_offset = 0
        for im in images:
            new_im.paste(im, (0, y_offset))
            y_offset += im.size[1]
        total_width = sum(widths)
        max_height = max(heights)
        new_im ='RGB', (total_width, max_height))

        x_offset = 0
        for im in images:
            new_im.paste(im, (x_offset, 0))
            x_offset += im.size[0]'test.jpg')
    return 'test.jpg'

Find unused npm packages in package.json

If you're using a Unix like OS (Linux, OSX, etc) then you can use a combination of find and egrep to search for require statements containing your package name:

find . -path ./node_modules -prune -o -name "*.js" -exec egrep -ni 'name-of-package' {} \;

If you search for the entire require('name-of-package') statement, remember to use the correct type of quotation marks:

find . -path ./node_modules -prune -o -name "*.js" -exec egrep -ni 'require("name-of-package")' {} \;


find . -path ./node_modules -prune -o -name "*.js" -exec egrep -ni "require('name-of-package')" {} \;

The downside is that it's not fully automatic, i.e. it doesn't extract package names from package.json and check them. You need to do this for each package yourself. Since package.json is just JSON this could be remedied by writing a small script that uses child_process.exec to run this command for each dependency. And make it a module. And add it to the NPM repo...

Resize to fit image in div, and center horizontally and vertically


.container {
    margin: 10px;
    width: 115px;
    height: 115px;
    line-height: 115px;
    text-align: center;
    border: 1px solid red;
    background-image: url("");
    background-repeat: no-repeat;
    background-position: center;
    background-size: contain;



<div class='container'>

<div class='container' style='width:50px;height:100px;line-height:100px'>

<div class='container' style='width:140px;height:70px;line-height:70px'>

Passing an array of parameters to a stored procedure

this is the best source:

create a split function using the link, and use it like:

DELETE YourTable
    FROM YourTable                           d
    LEFT OUTER JOIN dbo.splitFunction(@Parameter) s ON d.ID=s.Value
    WHERE s.Value IS NULL

I prefer the number table approach

This is code based on the above link that should do it for you...

Before you use my function, you need to set up a "helper" table, you only need to do this one time per database:

(Number int  NOT NULL,
DECLARE @x int
SET @x=0
WHILE @x<8000
    SET @x=@x+1
    INSERT INTO Numbers VALUES (@x)

use this function to split your string, which does not loop and is very fast:

CREATE FUNCTION [dbo].[FN_ListToTable]
     @SplitOn              char(1)              --REQUIRED, the character to split the @List string on
    ,@List                 varchar(8000)        --REQUIRED, the list to split apart
@ParsedList table
    ListValue varchar(500)

Takes the given @List string and splits it apart based on the given @SplitOn character.
A table is returned, one row per split item, with a column name "ListValue".
This function workes for fixed or variable lenght items.
Empty and null items will not be included in the results set.

Returns a table, one row per item in the list, with a column name "ListValue"

SELECT * FROM dbo.FN_ListToTable(',','1,12,123,1234,54321,6,A,*,|||,,,,B')


        (10 row(s) affected)


--SINGLE QUERY-- --this will not return empty rows
        FROM (SELECT
                  LTRIM(RTRIM(SUBSTRING(List2, number+1, CHARINDEX(@SplitOn, List2, number+1)-number - 1))) AS ListValue
                  FROM (
                           SELECT @SplitOn + @List + @SplitOn AS List2
                       ) AS dt
                      INNER JOIN Numbers n ON n.Number < LEN(dt.List2)
                  WHERE SUBSTRING(List2, number, 1) = @SplitOn
             ) dt2
        WHERE ListValue IS NOT NULL AND ListValue!=''


END --Function FN_ListToTable

you can use this function as a table in a join:

    Col1, COl2, Col3...
    FROM  YourTable
        INNER JOIN dbo.FN_ListToTable(',',@YourString) s ON  YourTable.ID = s.ListValue

here is your delete:

DELETE YourTable
    FROM YourTable                                d
    LEFT OUTER JOIN dbo.FN_ListToTable(',',@Parameter) s ON d.ID=s.ListValue
    WHERE s.ListValue IS NULL

SSL error SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

The file that you downloaded ( is a bundle of the root certificates from the major trusted certificate authorities. You said that the remote host has a self-signed SSL certificate, so it didn't use a trusted certificate. The openssl.cafile setting needs to point to the CA certificate that was used to sign the SSL certificate on the remote host. PHP 5.6 has been improved over previous versions of PHP to now verify peer certificates and host names by default (

You'll need to locate the CA certificate that was generated on the server that signed the SSL certificate and copy it to this server. The only other option is to disable verifying the peer, but that defeats the SSL security. If you DO want to try disabling verification, try this array with the code from my previous answer:

$contextOptions = array(
    'ssl' => array(
        'verify_peer' => false,
        'verify_peer_name' => false

Either way, if you're using self-signed certificates, you'll need to add the CA cert that was used to sign the remote host's SSL certificate to the trusted store on the server you're connecting from OR use stream contexts to use that certificate for each individual request. Adding it to the trusted certificates is the simplest solution. Just add the contents of the remote host's CA cert to the end of the cacert.pem file you downloaded.


fsockopen doesn't support stream contexts, so use stream_socket_client instead. It returns a resource that can be used with all the commands that fsockopen resources can.

This should be a drop in replacement for the snippet you have in your question:


$contextOptions = array(
    'ssl' => array(
        'verify_peer' => true, // You could skip all of the trouble by changing this to false, but it's WAY uncool for security reasons.
        'cafile' => '/etc/ssl/certs/cacert.pem',
        'CN_match' => '', // Change this to your certificates Common Name (or just comment this line out if not needed)
        'ciphers' => 'HIGH:!SSLv2:!SSLv3',
        'disable_compression' => true,

$context = stream_context_create($contextOptions);

$fp = stream_socket_client("tcp://{$host}:{$port}", $errno, $errstr, 20, STREAM_CLIENT_CONNECT, $context);

if (!$fp) {

    echo "$errstr ({$errno})<br />\n";


    $this->request = 'POST '.substr($this->url, strlen($this->host)).' HTTP/1.1'.$crlf
        .'Host: '.$this->host.$crlf
        .'Content-Length: '.$content_length.$crlf
        .'Connection: Close'.$crlf.$crlf

    fwrite($fp, $this->request);

    while (!feof($fp)) {
        $this->response .= fgets($fp);



Display back button on action bar

I think onSupportNavigateUp() is the best and Easiest way to do so, check the below steps. Step 1 is necessary, step two have alternative.

Step 1 showing back button: Add this line in onCreate() method to show back button.

assert getSupportActionBar() != null;   //null check
getSupportActionBar().setDisplayHomeAsUpEnabled(true);   //show back button

Step 2 implementation of back click: Override this method

public boolean onSupportNavigateUp() {  
    return true;  

thats it you are done
OR Step 2 Alternative: You can add meta to the activity in manifest file as

        android:value="MainActivity" />

Edit: If you are not using AppCompat Activity then do not use support word, you can use

getActionBar().setDisplayHomeAsUpEnabled(true); // In `OnCreate();`

// And override this method
public boolean onNavigateUp() { 
     return true; 

Thanks to @atariguy for comment.

What's the difference between a mock & stub?

A fake is a generic term that can be used to describe either a stub or a mock object (handwritten or otherwise), because they both look like the real object.

Whether a fake is a stub or a mock depends on how it’s used in the current test. If it’s used to check an interaction (asserted against), it’s a mock object. Otherwise, it’s a stub.

Fakes makes sure test runs smoothly. It means that reader of your future test will understand what will be the behavior of the fake object, without needing to read its source code (without needing to depend on external resource).

What does test run smoothly mean?
Forexample in below code:

 public void Analyze(string filename)
                    errorService.LogError("long file entered named:" + filename);
                catch (Exception e)
                    mailService.SendEMail("[email protected]", "ErrorOnWebService", "someerror");

You want to test mailService.SendEMail() method, to do that you need to simulate an Exception in you test method, so you just need to create a Fake Stub errorService class to simulate that result, then your test code will be able to test mailService.SendEMail() method. As you see you need to simulate a result which is from an another External Dependency ErrorService class.

Failed to load resource under Chrome

There is also the option of turning off the cache for network resources. This might be best for developing environments.

  1. Right-click chrome
  2. Go to 'inspect element'
  3. Look for the 'network' tab somewhere at the top. Click it.
  4. Check the 'disable cache' checkbox.

How to terminate process from Python using pid?

Using the awesome psutil library it's pretty simple:

p = psutil.Process(pid)
p.terminate()  #or p.kill()

If you don't want to install a new library, you can use the os module:

import os
import signal

os.kill(pid, signal.SIGTERM) #or signal.SIGKILL 

See also the os.kill documentation.

If you are interested in starting the command python if it is not running, and killing it otherwise, you can use psutil to do this reliably.

Something like:

import psutil
from subprocess import Popen

for process in psutil.process_iter():
    if process.cmdline() == ['python', '']:
        print('Process found. Terminating it.')
    print('Process not found: starting it.')
    Popen(['python', ''])

Sample run:

$python contains the code above
Process not found: starting it.
Process found. Terminating it.
Process not found: starting it.
$killall python
Process not found: starting it.
Process found. Terminating it.
Process not found: starting it.

Note: In previous psutil versions cmdline was an attribute instead of a method.

HTML/CSS--Creating a banner/header

You have a type-o:

its: height: 200x;

and it should be: height: 200px; also check the image url; it should be in the same directory it seems.

Also, dont use 'px' at null (aka '0') values. 0px, 0em, 0% is still 0. :)

top: 0px;

is the same with:

top: 0;

Good Luck!

jQuery selector for the label of a checkbox

This should do it:


If you have non alphanumeric characters in your id then you must surround the attr value with quotes:


VBA, if a string contains a certain letter

If you are looping through a lot of cells, use the binary function, it is much faster. Using "<> 0" in place of "> 0" also makes it faster:

If InStrB(1, myString, "a", vbBinaryCompare) <> 0

How do I import a .dmp file into Oracle?

I am Using Oracle Database Express Edition 11g Release 2.

Follow the Steps:

Open run SQl Command Line

Step 1: Login as system user

       SQL> connect system/tiger

Step 2 : SQL> CREATE USER UserName IDENTIFIED BY Password;

Step 3 : SQL> grant dba to UserName ;


Step 5:

             DATAFILE 'tbs_perm_03.dat'
             SIZE 8G
             AUTOEXTEND ON;

Open Command Prompt in Windows or Terminal in Ubuntu. Then Type:

Note : if you Use Ubuntu then replace " \" to " /" in path.

Step 6: C:\> imp UserName/password@localhost file=D:\abc\xyz.dmp log=D:\abc\abc_1.log full=y;


I hope you Find Right solution here.


DataColumn Name from DataRow (not DataTable)

You can make it easier in your code (if you're doing this a lot anyway) by using an extension on the DataRow object, like:

static class Extensions
    public static string GetColumn(this DataRow Row, int Ordinal)
        return Row.Table.Columns[Ordinal].ColumnName;

Then call it using:

string MyColumnName = MyRow.GetColumn(5);

'Use of Unresolved Identifier' in Swift

Because you haven't declared it. If you want to use a variable of another class you must use

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    var DestViewController : ViewController = segue.destinationViewController as ViewController
    DestViewController.signedIn = false

You have to put this code at the end of the NewClass code

How to markdown nested list items in Bitbucket?

This worked for me in Bitbucket Cloud.

Entering this:

* item a
* item b
** item b1
** item b2
* item3

I've got this:

enter image description here