Programs & Examples On #Html

HTML (Hyper Text Markup Language) is the standard markup language used for structuring web pages and formatting content. HTML describes the structure of a website semantically along with cues for presentation, making it a markup language, rather than a programming language. HTML works in conjunction primarily with CSS and JavaScript, adding presentation and behaviour to the pages. The most recent revision to the HTML specification is HTML5.2.

ASP.NET MVC get textbox input value

Try This.


@using (Html.BeginForm("Login", "Accounts", FormMethod.Post)) 
   <input type="text" name="IP" id="IP" />
   <input type="text" name="Name" id="Name" />

   <input type="submit" value="Login" />


public ActionResult Login(string IP, string Name)
    string s1=IP;//
    string s2=Name;//

If you can use model class

public ActionResult Login(ModelClassName obj)
    string s1=obj.IP;//
    string s2=obj.Name;//

Equal height rows in a flex container

If you know the items you are mapping through, you can accomplish this by doing one row at a time. I know it's a workaround, but it works.

For me I had 4 items per row, so I broke it up into two rows of 4 with each row height: 50%, get rid of flex-grow, have <RowOne /> and <RowTwo /> in a <div> with flex-column. This will do the trick

<div class='flexbox flex-column height-100-percent'>
   <RowOne class='flex height-50-percent' />
   <RowTwo class='flex height-50-percent' />

bootstrap initially collapsed element

another solution is to add toggle=false to the collapse target, this will stop it randomly opening and closing which happens if you just remove the "in"


<div class="accordion-heading">
    <a class="accordion-toggle"
    class="accordion-body collapse"
    <div class="span6">
        <div class="well well-small">
            <div class="accordion-toggle">
                ...some text...
    <div class="span2"></div>                            

Drawing an image from a data URL to a canvas

in javascript , using jquery for canvas id selection :

 var Canvas2 = $("#canvas2")[0];
        var Context2 = Canvas2.getContext("2d");
        var image = new Image();
        image.src = "images/eye.jpg";
        Context2.drawImage(image, 0, 0);


<canvas id="canvas2"></canvas>

Why is a div with "display: table-cell;" not affected by margin?

You can use inner divs to set the margin.

<div style="display: table-cell;">
   <div style="margin:5px;background-color: red;">1</div>
<div style="display: table-cell; ">
  <div style="margin:5px;background-color: green;">1</div>

JS Fiddle

HTML Upload MAX_FILE_SIZE does not appear to work

There IS A POINT in introducing MAX_FILE_SIZE client side hidden form field.

php.ini can limit uploaded file size. So, while your script honors the limit imposed by php.ini, different HTML forms can further limit an uploaded file size. So, when uploading video, form may limit* maximum size to 10MB, and while uploading photos, forms may put a limit of just 1mb. And at the same time, the maximum limit can be set in php.ini to suppose 10mb to allow all this.

Although this is not a fool proof way of telling the server what to do, yet it can be helpful.

  • HTML does'nt limit anything. It just forwards the server all form variable including MAX_FILE_SIZE and its value.

Hope it helped someone.

How to vertically align into the center of the content of a div with defined width/height?

I would say to add a paragraph with a period in it and style it like so:

<p class="center">.</p>

.center {font-size: 0px; margin-bottom: anyPercentage%;}

You may need to toy around with the percentages to get it right

Can I hide the HTML5 number input’s spin box?

input[type=number]::-webkit-inner-spin-button, _x000D_
input[type=number]::-webkit-outer-spin-button {_x000D_
     -webkit-appearance: none;
<input id="test" type="number">

Display HTML snippets in HTML

The tried and true method for HTML:

  1. Replace the & character with &amp;
  2. Replace the < character with &lt;
  3. Replace the > character with &gt;
  4. Optionally surround your HTML sample with <pre> and/or <code> tags.

How to embed images in html email

PHPMailer has the ability to automatically embed images from your HTML email. You have to give full path in the file system, when writing your HTML:

<img src="/var/www/host/images/photo.png" alt="my photo" />

It will automaticaly convert to:

<img src="cid:photo.png" alt="my photo" />

Creating a fixed sidebar alongside a centered Bootstrap 3 grid

As drew_w said, you can find a good example here.


<div id="wrapper">
    <div id="sidebar-wrapper">
        <ul class="sidebar-nav">
            <li class="sidebar-brand"><a href="#">Home</a></li>
            <li><a href="#">Another link</a></li>
            <li><a href="#">Next link</a></li>
            <li><a href="#">Last link</a></li>
    <div id="page-content-wrapper">
        <div class="page-content">
            <div class="container">
                <div class="row">
                    <div class="col-md-12">
                        <!-- content of page -->


#wrapper {
  padding-left: 250px;
  transition: all 0.4s ease 0s;

#sidebar-wrapper {
  margin-left: -250px;
  left: 250px;
  width: 250px;
  background: #CCC;
  position: fixed;
  height: 100%;
  overflow-y: auto;
  z-index: 1000;
  transition: all 0.4s ease 0s;

#page-content-wrapper {
  width: 100%;

.sidebar-nav {
  position: absolute;
  top: 0;
  width: 250px;
  list-style: none;
  margin: 0;
  padding: 0;

@media (max-width:767px) {

    #wrapper {
      padding-left: 0;

    #sidebar-wrapper {
      left: 0;
    } {
      position: relative;
      left: 250px;
    } #sidebar-wrapper {
      left: 250px;
      width: 250px;
      transition: all 0.4s ease 0s;



How to load all the images from one of my folder into my web page, using Jquery/Javascript

Use :

var dir = "Src/themes/base/images/";
var fileextension = ".png";
    //This will retrieve the contents of the folder if the folder is configured as 'browsable'
    url: dir,
    success: function (data) {
        //List all .png file names in the page
        $(data).find("a:contains(" + fileextension + ")").each(function () {
            var filename = this.href.replace(, "").replace("http://", "");
            $("body").append("<img src='" + dir + filename + "'>");

If you have other extensions, you can make it an array and then go through that one by one using in_array().

P.s : The above source code is not tested.

drag drop files into standard html file input

This is an improvement, bugfix, and modification of the example that William Entriken gave here. There were some issues with it. For example the normal button from <input type="file" /> didn't do anything (in case the user wanted to upload the file that way).

Notice: I am making a webapp that only I use, so this is only tested (and refined) for Firefox. I am sure though that this code is of value even if you develop for the crossbrowser situation.

function readFile(e) {
  var files;
  if ( {
  } else {
  if (files.length==0) {
    alert('What you dropped is not a file.');
  var file=files[0];
  document.getElementById('fileDragName').value =
  document.getElementById('fileDragSize').value = file.size
  document.getElementById('fileDragType').value = file.type
  reader = new FileReader();
  reader.onload = function(e) {
    document.getElementById('fileDragData').value =;
function getTheFile(e) {'#ccc';
<input type="file" onchange="readFile(event)">
<input id="fileDragName">
<input id="fileDragSize">
<input id="fileDragType">
<input id="fileDragData">
<div style="width:200px; height:200px; border: 10px dashed #ccc"
     ondragover="'#0c0';return false;"       
     ondrop="getTheFile(event); return false;"       

SPAN vs DIV (inline-block)

I know this Q is old, but why not use all DIVs instead of the SPANs? Then everything plays all happy together.


   <div> content1(divs,p, spans, etc) </div> 
   <div> content2(divs,p, spans, etc) </div> 
   <div> content3(divs,p, spans, etc) </div> 
   <div> content4(divs,p, spans, etc) </div> 
   <div> content5(divs,p, spans, etc) </div> 
   <div> content6(divs,p, spans, etc) </div> 

how to call a onclick function in <a> tag?

You should read up on the onclick html attribute and the documentation. Below is what you want.

<a href='#' onclick='"", "myWin", "scrollbars=yes,width=400,height=650"); return false;'>1</a>


Make child div stretch across width of page

I know this post is old, in case someone stumbles upon it in 2019, this would work try it.

<div id="container">
<div id="help_panel">
<div class="help_panel_extra_if_you_want"> //then if you want to add some height and width if you want, do this.


left: 0px;
top: 0px;
right: 0px;
z-index: 100;
display: -webkit-box;
display: -webkit-flex;
display: -ms-flexbox;
display: flex;
-webkit-box-orient: vertical;
-webkit-box-direction: normal;
-webkit-flex-direction: column;
-ms-flex-direction: column;
flex-direction: column;
-webkit-box-pack: start;
-webkit-justify-content: flex-start;
-ms-flex-pack: start;
justify-content: flex-start;    
position: relative;

#help_panel {
display: -webkit-box;
display: -webkit-flex;
display: -ms-flexbox;
display: flex;
padding-right: 24px;
padding-left: 18px;
-webkit-box-orient: vertical;
-webkit-box-direction: normal;
-webkit-flex-direction: column;
-ms-flex-direction: column;
flex-direction: column;
-webkit-box-align: center;
-webkit-align-items: center;
-ms-flex-align: center;
align-items: center;

position: relative;
-webkit-box-orient: horizontal;
-webkit-box-direction: normal;
-webkit-flex-direction: row;
-ms-flex-direction: row;
flex-direction: row;
-webkit-box-pack: justify;
-webkit-justify-content: space-between;
-ms-flex-pack: justify;
justify-content: space-between;
align-items: center;
display: flex;
width: 95%;
max-width: 1200px;

SHOULD GIVE YOU SOMETHING LIKE THIS This is how it would look, adjust the width and margin and padding to achieve what you want

Refresh a page using JavaScript or HTML

window.location.reload(); in JavaScript

<meta http-equiv="refresh" content="1"> in HTML (where 1 = 1 second).

Change image size via parent div


  <div style="height:42px;width:42px">
  <img src="http://someimage.jpg">

Is it okay to use this code?

  <div class= "box">
  <img src= "http://someimage.jpg" class= "img">

  <style type="text/css">
  .box{width: 42; height: 42;}
  .img{width: 20; height:20;}

Just trying, though late. :3 For someone else reading this, letme know if the way i wrote the code were not good. im new in this kind of language. and i still want to learn more.

How to find children of nodes using BeautifulSoup

Yet another method - create a filter function that returns True for all desired tags:

def my_filter(tag):
    return ( == 'a' and == 'li' and
        'test' in tag.parent['class'])

Then just call find_all with the argument:

for a in soup(my_filter): # or soup.find_all(my_filter)
    print a

Add CSS3 transition expand/collapse

This is my solution that adjusts the height automatically:

function growDiv() {_x000D_
  var growDiv = document.getElementById('grow');_x000D_
  if (growDiv.clientHeight) {_x000D_ = 0;_x000D_
  } else {_x000D_
    var wrapper = document.querySelector('.measuringWrapper');_x000D_ = wrapper.clientHeight + "px";_x000D_
  document.getElementById("more-button").value = document.getElementById("more-button").value == 'Read more' ? 'Read less' : 'Read more';_x000D_
#more-button {_x000D_
  border-style: none;_x000D_
  background: none;_x000D_
  font: 16px Serif;_x000D_
  color: blue;_x000D_
  margin: 0 0 10px 0;_x000D_
#grow input:checked {_x000D_
  color: red;_x000D_
#more-button:hover {_x000D_
  color: black;_x000D_
#grow {_x000D_
  -moz-transition: height .5s;_x000D_
  -ms-transition: height .5s;_x000D_
  -o-transition: height .5s;_x000D_
  -webkit-transition: height .5s;_x000D_
  transition: height .5s;_x000D_
  height: 0;_x000D_
  overflow: hidden;_x000D_
<input type="button" onclick="growDiv()" value="Read more" id="more-button">_x000D_
<div id='grow'>_x000D_
  <div class='measuringWrapper'>_x000D_
    <div class="text">Here is some more text: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum vitae urna nulla. Vivamus a purus mi. In hac habitasse platea dictumst. In ac tempor quam. Vestibulum eleifend vehicula ligula, et cursus nisl gravida sit_x000D_
      amet. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.</div>_x000D_

I used the workaround that r3bel posted: Can you use CSS3 to transition from height:0 to the variable height of content?

How to remove underline from a link in HTML?

I suggest to use :hover to avoid underline if mouse pointer is over an anchor

a:hover {

Write HTML string in JSON

One way is to replace the double quotes in the HTML with single quotes but using double quotes has become the standard convention for attribute values in HTML.

The better option is to escape the double quotes in json and other characters that need to be escaped.

You can get some more details about escaping here: Where can I find a list of escape characters required for my JSON ajax return type?

How to keep form values after post

you can save them into a $_SESSION variable and then when the user calls that page again populate all the inputs with their respective session variables.

Node.js Generate html

If you want to create static files, you can use Node.js File System Library to do that. But if you are looking for a way to create dynamic files as a result of your database or similar queries then you will need a template engine like SWIG. Besides these options you can always create HTML files as you would normally do and serve them over Node.js. To do that, you can read data from HTML files with Node.js File System and write it into response. A simple example would be:

var http = require('http');
var fs   = require('fs');

http.createServer(function (req, res) {
  fs.readFile(req.params.filepath, function (err, content) {
    if(!err) {
    } else {

But I suggest you to look into some frameworks like Express for more useful solutions.

Redirect website after certain amount of time

Use this simple javascript code to redirect page to another page using specific interval of time...

Please add this code into your web site page, which is you want to redirect :

<script type="text/javascript">
   },3000); /* 1000 = 1 second*/

How to use CSS to surround a number with a circle?

If it's 20 and lower, you can just use the unicode characters ? ? ... ?

scrollTop animation without jquery


<button onclick="scrollToTop(1000);"></button>

1# JavaScript (linear):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const totalScrollDistance = document.scrollingElement.scrollTop;
    let scrollY = totalScrollDistance, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollY will be -Infinity
            scrollY -= totalScrollDistance * (newTimestamp - oldTimestamp) / duration;
            if (scrollY <= 0) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = scrollY;
        oldTimestamp = newTimestamp;

2# JavaScript (ease in and out):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const cosParameter = document.scrollingElement.scrollTop / 2;
    let scrollCount = 0, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollCount will be Infinity
            scrollCount += Math.PI * (newTimestamp - oldTimestamp) / duration;
            if (scrollCount >= Math.PI) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = cosParameter + cosParameter * Math.cos(scrollCount);
        oldTimestamp = newTimestamp;
  - pi is the length/end point of the cosinus intervall (see below)
  - newTimestamp indicates the current time when callbacks queued by requestAnimationFrame begin to fire.
    (for more information see
  - newTimestamp - oldTimestamp equals the delta time

    a * cos (bx + c) + d                        | c translates along the x axis = 0
  = a * cos (bx) + d                            | d translates along the y axis = 1 -> only positive y values
  = a * cos (bx) + 1                            | a stretches along the y axis = cosParameter = window.scrollY / 2
  = cosParameter + cosParameter * (cos bx)  | b stretches along the x axis = scrollCount = Math.PI / (scrollDuration / (newTimestamp - oldTimestamp))
  = cosParameter + cosParameter * (cos scrollCount * x)


  • Duration in milliseconds (1000ms = 1s)
  • Second script uses the cos function. Example curve:

enter image description here

3# Simple scrolling library on Github

How to make a checkbox checked with jQuery?

I think you should use prop(), if you are using jQuery 1.6 onwards.

To check it you should do:

$('#test').prop('checked', true);

to uncheck it:

$('#test').prop('checked', false);

How do I replicate a \t tab space in HTML?

You can use this &emsp; or &ensp;

It works on Visual Studio

Getting a link to go to a specific section on another page

You can simply use

 <a href="directry/filename.html#section5" >click me</a>

to link to a section/id of another page by

How to completely hide the navigation bar in iPhone / HTML5

The problem with all of the answers given so far is that on the something borrowed site, the Mac bar remains totally hidden when scrolling up, and the provided answers don't accomplish that.

If you just use scrollTo and then the user later scrolls up, the nav bar is revealed again, so it seems you have to put the whole site inside of a div and force scrolling to happen inside of that div rather than on the body which keeps the nav bar hidden during scrolling in any direction.

You can, however, still reveal the nav bar by touching near the top of the screen on apple devices.

Dynamically adding HTML form field using jQuery

This will insert a new element after the input field with id "password".

  var newInput = $("<input name='new_field' type='text'>");

Not sure if this answers your question.

Parse HTML in Android

We all know that programming have endless possibilities.There are numbers of solutions available for a single problem so i think all of the above solutions are perfect and may be helpful for someone but for me this one save my day..

So Code goes like this

  private void getWebsite() {
    new Thread(new Runnable() {
      public void run() {
        final StringBuilder builder = new StringBuilder();

        try {
          Document doc = Jsoup.connect("").get();
          String title = doc.title();
          Elements links ="a[href]");


          for (Element link : links) {
            builder.append("\n").append("Link : ").append(link.attr("href"))
            .append("\n").append("Text : ").append(link.text());
        } catch (IOException e) {
          builder.append("Error : ").append(e.getMessage()).append("\n");

        runOnUiThread(new Runnable() {
          public void run() {

You just have to call the above function in onCreate Method of your MainActivity

I hope this one is also helpful for you guys.

Also read the original blog at Medium

font size in html code

Try this:

      <td style="padding-left: 5px;
                 padding-bottom: 3px;">
        <strong style="font-size: 35px;">Datum:</strong><br />
        November 2010 

Notice that I also included the table-tag, which you seem to have forgotten. This has to be included if you want this to appear as a table.

HTML5 iFrame Seamless Attribute

It's not supported correctly yet.

Chrome 31 (and possibly an earlier version) supports some parts of the attribute, but it is not fully supported.

Why can't I do <img src="C:/localfile.jpg">?

I see two possibilities for what you are trying to do:

  1. You want your webpage, running on a server, to find the file on the computer that you originally designed it?

  2. You want it to fetch it from the pc that is viewing at the page?

Option 1 just doesn't make sense :)

Option 2 would be a security hole, the browser prohibits a web page (served from the web) from loading content on the viewer's machine.

Kyle Hudson told you what you need to do, but that is so basic that I find it hard to believe this is all you want to do.

FormData.append("key", "value") is not working

New in Chrome 50+ and Firefox 39+ (resp. 44+):

  • formdata.entries() (combine with Array.from() for debugability)
  • formdata.get(key)
  • and more very useful methods

Original answer:

What I usually do to 'debug' a FormData object, is just send it (anywhere!) and check the browser logs (eg. Chrome devtools' Network tab).

You don't need a/the same Ajax framework. You don't need any details. Just send it:

var xhr = new XMLHttpRequest;'POST', '/', true);


Failed to load resource: the server responded with a status of 404 (Not Found) css

you have defined the public dir in app root/public

app.use(express.static(__dirname + '/public')); 

so you have to use:


Twitter Bootstrap tabs not working: when I click on them nothing happens

Since i'm working with Bootstrap Javascript Modules instead of loading the entire Bootstrap Javascript, my tabs were not working because i forgot to load load/include/ the node_modules/bootstrap/js/tab.js file.

enter image description here

After including it, it worked...

Good Luck

After submitting a POST form open a new window showing the result

var urlAction = 'whatever.php';
var data = {param1:'value1'};

var $form = $('<form target="_blank" method="POST" action="' + urlAction + '">');
$.each(data, function(k,v){
    $form.append('<input type="hidden" name="' + k + '" value="' + v + '">');

jQuery UI accordion that keeps multiple sections open?

Even simpler, have it labeled in each li tag's class attribute and have jquery to loop through each li to initialize the accordion.

100% Min Height CSS layout

I am using the following one: CSS Layout - 100 % height


The #container element of this page has a min-height of 100%. That way, if the content requires more height than the viewport provides, the height of #content forces #container to become longer as well. Possible columns in #content can then be visualised with a background image on #container; divs are not table cells, and you don't need (or want) the physical elements to create such a visual effect. If you're not yet convinced; think wobbly lines and gradients instead of straight lines and simple color schemes.

Relative positioning

Because #container has a relative position, #footer will always remain at its bottom; since the min-height mentioned above does not prevent #container from scaling, this will work even if (or rather especially when) #content forces #container to become longer.


Since it is no longer in the normal flow, padding-bottom of #content now provides the space for the absolute #footer. This padding is included in the scrolled height by default, so that the footer will never overlap the above content.

Scale the text size a bit or resize your browser window to test this layout.

html,body {
    height:100%; /* needed for container min-height */


h1 { 
    font:1.5em georgia,serif; 
    margin:0.5em 0;

h2 {
    font:1.25em georgia,serif; 
    margin:0 0 0.5em;
    h1, h2, a {

p { 
    margin:0 0 1em;

div#container {
    position:relative; /* needed for footer positioning*/
    margin:0 auto; /* center, not in IE5 */

    height:auto !important; /* real browsers */
    height:100%; /* IE6: treaded as min-height*/

    min-height:100%; /* real browsers */

div#header {
    background:#ddd url("../csslayout.gif") 98% 10px no-repeat;
    border-bottom:6px double gray;
    div#header p {

div#content {
    padding:1em 1em 5em; /* bottom padding for footer */
    div#content p {
        padding:0 1em;

div#footer {
    bottom:0; /* stick to bottom */
    border-top:6px double gray;
div#footer p {

Works fine for me.

How to reduce the space between <p> tags?

A more real-world example:

p { margin: 10px 0;}

How to show validation message below each textbox using jquery?

This is the simple solution may work for you.

Check this solution

$('form').on('submit', function (e) {
var emailBox=$("#email");
var passBox=$("#password");
if (!emailBox.val() || !passBox.val()) {
    $(".validationText").text("Please Enter Value").show();
else if(!IsEmail(emailBox.val()))
    emailBox.prev().text("Invalid E-mail").show();
$("input#email, input#password").focus(function(){

Vertical Text Direction


The text-orientation CSS property sets the orientation of the text characters in a line. It only affects text in vertical mode (when writing-mode is not horizontal-tb). It is useful for controlling the display of languages that use vertical script, and also for making vertical table headers.

writing-mode: vertical-rl;
text-orientation: mixed;

You can also review all the Syntax here

/* Keyword values */
text-orientation: mixed;
text-orientation: upright;
text-orientation: sideways-right;
text-orientation: sideways;
text-orientation: use-glyph-orientation;

/* Global values */
text-orientation: inherit;
text-orientation: initial;
text-orientation: unset;

CSS last-child selector: select last-element of specific class, not last child inside of parent?

:last-child only works when the element in question is the last child of the container, not the last of a specific type of element. For that, you want :last-of-type

As per @BoltClock's comment, this is only checking for the last article element, not the last element with the class of .comment.

body {_x000D_
  background: black;_x000D_
.comment {_x000D_
  width: 470px;_x000D_
  border-bottom: 1px dotted #f0f0f0;_x000D_
  margin-bottom: 10px;_x000D_
.comment:last-of-type {_x000D_
  border-bottom: none;_x000D_
  margin-bottom: 0;_x000D_
<div class="commentList">_x000D_
  <article class="comment " id="com21"></article>_x000D_
  <article class="comment " id="com20"></article>_x000D_
  <article class="comment " id="com19"></article>_x000D_
  <div class="something"> hello </div>_x000D_

Question mark characters displaying within text, why is this?

I usually curse MS word and then run the following Wscript.

// replace with path to a file that needs cleaning
PATH = "test.html"

var go=WScript.CreateObject("Scripting.FileSystemObject");
var content=go.GetFile(PATH).OpenAsTextStream().ReadAll();
var out=go.CreateTextFile("clean-"+PATH, true);

// symbols


Using for loop inside of a JSP

You concrete problem is caused because you're mixing discouraged and old school scriptlets <% %> with its successor EL ${}. They do not share the same variable scope. The allFestivals is not available in scriptlet scope and the i is not available in EL scope.

You should install JSTL (<-- click the link for instructions) and declare it in top of JSP as follows:

<%@taglib prefix="c" uri=""%>

and then iterate over the list as follows:

<c:forEach items="${allFestivals}" var="festival">

(beware of possible XSS attack holes, use <c:out> accordingly)

Don't forget to remove the <jsp:useBean> as it has no utter value here when you're using a servlet as model-and-view controller. It would only lead to confusion. See also our servlets wiki page. Further you would do yourself a favour to disable scriptlets by the following entry in web.xml so that you won't accidently use them:


How to insert spaces/tabs in text using HTML/CSS

If you're asking for tabs to align stuff in some lines, you can use <table>.

Putting each line in <tr> ... </tr>. And each element inside that line in <td> ... </td>. And of course you can always control the padding of each table cell to adjust the space between them.

This will make them aligned and they will look pretty nice :)

jQuery val is undefined?

This is stupid but for future reference. I did put all my code in:

$(document).ready(function () {
    //your jQuery function

But still it wasn't working and it was returning undefined value. I check my HTML DOM

<input id="username" placeholder="Username"></input>

and I realised that I was referencing it wrong in jQuery:

var user_name = $('#user_name').val();

Making it:

var user_name = $('#username').val();

solved my problem.

So it's always better to check your previous code.

Thin Black Border for a Table

Style the td and th instead

td, th {
    border: 1px solid black;

And also to make it so there is no spacing between cells use:

table {
    border-collapse: collapse;

(also note, you have border-style: none; which should be border-style: solid;)

See an example here:

Onclick event to remove default value in a text input field

Use onclick="this.value=''":

<input name="Name" value="Enter Your Name" onclick="this.value=''">

How can I add a Google search box to my website?

Sorry for replying on an older question, but I would like to clarify the last question.

You use a "get" method for your form. When the name of your input-field is "g", it will make a URL like this:[value from input-field]

But when you search with google, you notice the following URL:

Google uses the "q" Querystring variable as it's search-query. Therefor, renaming your field from "g" to "q" solved the problem.

Protect image download

1. Disable the Right Click on all Images

let allImages = document.querySelectorAll("img");
    value.oncontextmenu = (e)=>{

2. Disable the Pointer Event Using CSS

    pointer-events: none;

3. Put a transparent overlay over all the Images

<div class="imageContainer">
    <div class="overlayDiv"></div>
    <img src="Image.jpg" alt="Image">

And some CSS like this

    position: relative;
    position: absolute;
    width: 100%;
    height: auto;
    top: 0px;
    left: 0px;
    position: absolute;
    width: 100%;
    height: auto;
    top: 0px;
    left: 0px;
    background-color: transparent;
    z-index: 2;

4. Put your Image as a Background Image

    background-image: url(Image.jpg);
    background-size: cover;

These methods will only work on normal users because they most probably don't know about the inspector or how to check source code.
But a web developer can easily download these files, there is no such way you can disable the inspector completely.

At the end i would like to add few words.

Technically, Now think about this you are sending a Image from your server to another computer over HTTP, and you are at the same time trying to prevent it, it doesn't make any sense.....

you should always assume that anything that enters the machine of the user can be retrieved back now or later, no matter how hard you try, to hide it with encryption or maybe like youtube, sending the thing in chunks, and collecting them in browser.

getting the image ultimately is hard for a common user but not for people with a lot of technical background, maybe they are intercepting the entire network on Operating System Level, how you gonna stop them there.

How to fix getImageData() error The canvas has been tainted by cross-origin data?

As others have said you are "tainting" the canvas by loading from a cross origins domain.

However, you may be able to prevent this by simply setting:

img.crossOrigin = "Anonymous";

This only works if the remote server sets the following header appropriately:

Access-Control-Allow-Origin "*"

The Dropbox file chooser when using the "direct link" option is a great example of this. I use it on to hoover up images from the remote dropbox image url, into my canvas, and then submit the image data back into my server. All in javascript

Bootstrap 3 truncate long text inside rows of a table in a responsive way

This is what I achieved, but had to set width, and it cannot be percentual.

  width:250px; _x000D_
  white-space: nowrap; _x000D_
  overflow: hidden; _x000D_
  text-overflow: ellipsis;_x000D_
table tr td {_x000D_
padding: 5px_x000D_
table tr td {_x000D_
background: salmon_x000D_
table tr td:first-child {_x000D_
background: lightsalmon_x000D_
<link href="" rel="stylesheet"/>_x000D_
<script src=""></script>_x000D_
        <td>Quisque dignissim ante in tincidunt gravida. Maecenas lectus turpis</td>_x000D_
         <div class="trunc">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum._x000D_

or this:

How to make a vertical line in HTML

One other option is to use a 1-pixel image, and set the height - this option would allow you to float it to where you need to be.

Not the most elegant solution though.

Set the default value in dropdownlist using jQuery

$('#userZipFiles option').prop('selected', function() {
        return this.defaultSelected;

HTML form action and onsubmit issues


onsubmit="return checkRegistration()"

How to submit an HTML form on loading the page?

You missed the closing tag for the input fields, and you can choose any one of the events, ex: onload, onclick etc.

(a) Onload event:

<script type="text/javascript">

(b) Onclick Event:

<form name="frm1" id="frm1" action="../somePage" method="post">
    Please Waite... 
    <input type="hidden" name="uname" id="uname" value=<?php echo $uname;?> />
    <input type="hidden" name="price" id="price" value=<?php echo $price;?> />
    <input type="text" name="submit" id="submit" value="submit">
<script type="text/javascript">

Delete all rows in an HTML table

I needed to delete all rows except the first and solution posted by @strat but that resulted in uncaught exception (referencing Node in context where it does not exist). The following worked for me.

var myTable = document.getElementById("myTable");
var rowCount = myTable.rows.length;
for (var x=rowCount-1; x>0; x--) {

prevent refresh of page when button inside form clicked

All you need to do is put a type tag and make the type button.

<button id="btnId" type="button">Hide/Show</button>

That solves the issue

Getting value of HTML text input

If your page is refreshed on submitting - yes, but only through the querystring: (You must use method "GET" then). Else, you can return its value from the php script.

How to Right-align flex item?

For those using Angular and Flex-Layout, use the following on the flex-item container:

<div fxLayout="row" fxLayoutAlign="flex-end">

See fxLayoutAlign docs here and the full fxLayout docs here.

How do I put hint in a asp:textbox

Adding placeholder attributes from code-behind:

txtFilterTerm.Attributes.Add("placeholder", "Filter" + Filter.Name);


txtFilterTerm.Attributes["placeholder"] = "Filter" + Filter.Name;

Adding placeholder attributes from aspx Page

<asp:TextBox type="text" runat="server" id="txtFilterTerm" placeholder="Filter" />


<input type="text" id="txtFilterTerm" placeholder="Filter"/>

Shortest way to print current year in a website

You've asked for a JavaScript solution, so here's the shortest I can get it:

<script>document.write(new Date().getFullYear())</script>

That will work in all browsers I've run across.

How I got there:

  • You can just call getFullYear directly on the newly-created Date, no need for a variable. new Date().getFullYear() may look a bit odd, but it's reliable: the new Date() part is done first, then the .getFullYear().
  • You can drop the type, because JavaScript is the default; this is even documented as part of the HTML5 specification, which is likely in this case to be writing up what browsers already do.
  • You can drop the semicolon at the end for one extra saved character, because JavaScript has "automatic semicolon insertion," a feature I normally despise and rail against, but in this specific use case it should be safe enough.

It's important to note that this only works on browsers where JavaScript is enabled. Ideally, this would be better handled as an offline batch job (sed script on *nix, etc.) once a year, but if you want the JavaScript solution, I think that's as short as it gets. (Now I've gone and tempted fate.)

However, unless you're using a server that can only provide static files, you're probably better off doing this on the server with a templating engine and using caching headers to allow the resulting page to be cached until the date needs to change. That way, you don't require JavaScript on the client. Using a non-defer/async script tag in the content also briefly delays the parsing and presentation of the page (for exactly this reason: because the code in the script might use document.write to output HTML).

How to get box-shadow on left & right sides only

I tried to copy the bootstrap shadow-sm just in the right side, here is my code:

    box-shadow: 5px 0 5px -4px rgba(237, 241, 235, 0.8);

display: inline-block extra margin

After struggling with this issue too many times I found a very elegant solution in HTML 5. In HTML 5 you should not close several (li,p,etc) tags; the ambition to become XML is forever gone. For example, the preferred way to do a list is:

       <a ...>...</a>
       <a ...>...</a>

Browsers MUST close the LI and they must do this without introducing whitespace, solving this problem. If you still have the XML mindset it feels wrong but once you get over that it saves many a nightmare. And this is not a hack since it relies on the wording of the HTML 5 spec. Better, since not closing tags is pervasive I expect no compatibility issues (not tested though). Bonus is that HTML formatters handle this well.

A little worked out example:

An URL to a Windows shared folder

I think there are two issues:

  1. You need to escape the slashes.
  2. Browser security.


  1. I checked one of mine, I have the pattern:

    <a href="file://///server01\fshare\dir1\dir2\dir3">useful link </a>

    Please note that we ended up with 5 slashes after the protocol (file:)

  2. Firefox will try to prevent cross site scripting. My solution was to modify prefs.js in the profile directory. You will add two lines:

    user_pref("capability.policy.localfilelinks.checkloaduri.enabled", "allAccess");
    user_pref("capability.policy.localfilelinks.sites", "");

How to modify STYLE attribute of element with known ID using JQuery

Use the CSS function from jQuery to set styles to your items :

$('#buttonId').css({ "background-color": 'brown'});

Make an image responsive - the simplest way

Width: 100% will break it when you view on a wider are.

Following is Bootstrap's img-responsive

max-width: 100%; 
height: auto;

How to Auto resize HTML table cell to fit the text size

You can try this:


        <td class="shrink">element1</td>
        <td class="shrink">data</td>
        <td class="shrink">junk here</td>
        <td class="expand">last column</td>
        <td class="shrink">elem</td>
        <td class="shrink">more data</td>
        <td class="shrink">other stuff</td>
        <td class="expand">again, last column</td>
        <td class="shrink">more</td>
        <td class="shrink">of </td>
        <td class="shrink">these</td>
        <td class="expand">rows</td>


table {
    border: 1px solid green;
    border-collapse: collapse;

table td {
    border: 1px solid green;

table td.shrink {
table td.expand {
    width: 99%

Always show vertical scrollbar in <select>


overflow-y: scroll

in your css bud.

How to set page content to the middle of screen?

I'm guessing you want to center the box both vertically and horizontally, regardless of browser window size. Since you have a fixed width and height for the box, this should work:




div {
    height: 200px;
    width: 400px;
    background: black;

    position: fixed;
    top: 50%;
    left: 50%;
    margin-top: -100px;
    margin-left: -200px;

The div should remain in the center of the screen even if you resize the browser. Just replace the margin-top and margin-left with half of the height and width of your table.

Edit: Credit goes to CSS-Tricks, where I got the original idea.

Is <div style="width: ;height: ;background: "> CSS?

For example :

<div style="height:100px; width:100px; background:#000000"></div>


you give css to div of height and width having 100px and background as black.

PS : try to avoid inline-css you can make external CSS and import in your html file.

you can refer here for CSS

hope this helps.

How can I display a tooltip on an HTML "option" tag?

At least on firefox, you can set a "title" attribute on the option tag:

<option value="" title="Tooltip">Some option</option>

Force table column widths to always be fixed regardless of contents

Specify the width of the table:

    table-layout: fixed;
    width: 100px;

See jsFiddle

How to check whether a select box is empty using JQuery/Javascript

To check whether select box has any values:

if( $('#fruit_name').has('option').length > 0 ) {

To check whether selected value is empty:

if( !$('#fruit_name').val() ) { 

How do I center an anchor element in CSS?


margin: 0 auto;

Hope that helps somebody out.

Apache giving 403 forbidden errors

In my case it was failing as the IP of my source server was not whitelisted in the target server.

For e.g. I was trying to access from application running on my source server. On source server find IP by ifconfig

This IP should be whitelisted in the target Server's apache config file. If its not then get it whitelist.

Steps to add a IP for whitelisting (if you control the target server as well) ssh to the apache server sudo su - cd /usr/local/apache/conf/extra (actual directories can be different based on your config)

Find the config file for the target application for e.g. prodcat-443.conf

RewriteCond %{REMOTE_ADDR} <YOUR Server's IP> 
for e.g.
RewriteCond %{REMOTE_ADDR} !^192\.68\.2\.98

Hope this helps someone

Making a button invisible by clicking another button in HTML

write this

To hide


to show


Disable native datepicker in Google Chrome

This worked for me:

// Hide Chrome datetime picker
$('input[type="datetime-local"]').attr('type', 'text');

// Reset date values

Even though the value of the date fields was still there and correct, it did not display. That's why I reset the date values from my view model.

How to call a PHP function on the click of a button

The onclick attribute in HTML calls JavaScript functions, not PHP functions.

Bootstrap Alert Auto Close

Using a fadeTo() that is fading to an opacity of 500 in 2 seconds in "I Can Has Kittenz"'s code isn't readable to me. I think it's better using other options like a delay()

$(".alert").delay(4000).slideUp(200, function() {

Confirm button before running deleting routine from website

Call this function onclick of button

/*pass whatever you want instead of id */
function doConfirm(id) {
    var ok = confirm("Are you sure to Delete?");
    if (ok) {
        if (window.XMLHttpRequest) {
            // code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {
            // code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                window.location = "create_dealer.php";
        }"GET", "delete_dealer.php?id=" + id);
        // file name where delete code is written

How do I change the text of a span element using JavaScript?

For some reason, it seems that using "text" attribute is the way to go with most browsers. It worked for me

$("#span_id").text("text value to assign");

How do I replace text inside a div element?

Use innerText if you can't assume structure - Use Text#data to update existing text Performance Test

How to disable an input type=text?

Get a reference to your input box however you like (eg document.getElementById('mytextbox')) and set its readonly property to true:

myInputBox.readonly = true;

Alternatively you can simply add this property inline (no JavaScript needed):

<input type="text" value="from db" readonly="readonly" />

How to use the "required" attribute with a "radio" input field

Here is a very basic but modern implementation of required radio buttons with native HTML5 validation:

fieldset { 
  display: block;
  margin-left: 0;
  margin-right: 0;
  padding-top: 0;
  padding-bottom: 0;
  padding-left: 0;
  padding-right: 0;
  border: none;
body {font-size: 15px; font-family: serif;}
input {
  background: transparent;
  border-radius: 0px;
  border: 1px solid black;
  padding: 5px;
  box-shadow: none!important;
  font-size: 15px; font-family: serif;
input[type="submit"] {padding: 5px 10px; margin-top: 5px;}
label {display: block; padding: 0 0 5px 0;}
form > div {margin-bottom: 1em; overflow: auto;}
.hidden {
  opacity: 0; 
  position: absolute; 
  pointer-events: none;
.checkboxes label {display: block; float: left;}
input[type="radio"] + span {
  display: block;
  border: 1px solid black;
  border-left: 0;
  padding: 5px 10px;
label:first-child input[type="radio"] + span {border-left: 1px solid black;}
input[type="radio"]:checked + span {background: silver;}
    <label for="name">Name (optional)</label>
    <input id="name" type="text" name="name">
  <div class="checkboxes">
    <label for="male"><input id="male" type="radio" name="gender" value="male" class="hidden" required="required"><span>Male</span></label>
    <label for="female"><input id="female" type="radio" name="gender" value="female" class="hidden" required="required"><span>Female </span></label>
    <label for="other"><input id="other" type="radio" name="gender" value="other" class="hidden" required="required"><span>Other</span></label>
  <input type="submit" value="Send" />

Although I am a big fan of the minimalistic approach of using native HTML5 validation, you might want to replace it with Javascript validation on the long run. Javascript validation gives you far more control over the validation process and it allows you to set real classes (instead of pseudo classes) to improve the styling of the (in)valid fields. This native HTML5 validation can be your fall-back in case of broken (or lack of) Javascript. You can find an example of that here, along with some other suggestions on how to make Better forms, inspired by Andrew Cole.

Bootstrap date time picker

In order to run the bootstrap date time picker you need to include Moment.js as well. Here is the working code sample in your case.

<!DOCTYPE html>_x000D_
    <html lang="en">_x000D_
      <meta charset="utf-8">_x000D_
      <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
      <link rel="stylesheet" href="">_x000D_
      <script src=""></script>_x000D_
      <script src=""></script>_x000D_
      <!-- <link rel="stylesheet" type="text/css" href="css/bootstrap-datetimepicker.css"> -->_x000D_
      <script type="text/javascript" src=""></script>_x000D_
      <link rel="stylesheet" type="text/css" href=""> _x000D_
      <link rel="stylesheet" type="text/css" href=""> _x000D_
      <script type="text/javascript" src=""></script>_x000D_
       <div class="container">_x000D_
          <div class="row">_x000D_
            <div class='col-sm-6'>_x000D_
                <div class="form-group">_x000D_
                    <div class='input-group date' id='datetimepicker1'>_x000D_
                        <input type='text' class="form-control" />_x000D_
                        <span class="input-group-addon">_x000D_
                            <span class="glyphicon glyphicon-calendar"></span>_x000D_
            <script type="text/javascript">_x000D_
                $(function () {_x000D_

Setting button text via javascript

The value of a button element isn't the displayed text, contrary to what happens to input elements of type button.

You can do this :

 b.appendChild(document.createTextNode('test value'));


Converting HTML to Excel?

Change the content type to ms-excel in the html and browser shall open the html in the Excel as xls. If you want control over the transformation of HTML to excel use POI libraries to do so.

How can I make a TextArea 100% width without overflowing when padding is present in CSS?

The answer to many CSS formatting problems seems to be "add another <div>!"

So, in that spirit, have you tried adding a wrapper div to which the border/padding are applied and then putting the 100% width textarea inside of that? Something like (untested):

  border:1px solid #999999;_x000D_
  margin:5px 0;_x000D_
<div style="display: block;" id="rulesformitem" class="formitem">_x000D_
  <label for="rules" id="ruleslabel">Rules:</label>_x000D_
  <div class="textwrapper"><textarea cols="2" rows="10" id="rules"/></div>_x000D_

Div vertical scrollbar show

Have you tried overflow-y:auto ? It is not exactly what you want, as the scrollbar will appear only when needed.

HTML 5: Is it <br>, <br/>, or <br />?

<br> works just fine. The stricter versions like XHTML require you to add the closing, and really old versions of HTML that do not include a DOCTYPE make <br> a non-void tag, like <br></br>.

Sum up: <br> is fine. Other ones are also just fine.

How to properly reference local resources in HTML?

  • A leading slash tells the browser to start at the root directory.
  • If you don't have the leading slash, you're referencing from the current directory.
  • If you add two dots before the leading slash, it means you're referencing the parent of the current directory.

Take the following folder structure

demo folder structure


  • the ROOT checkmark is green,
  • the second checkmark is orange,
  • the third checkmark is purple,
  • the forth checkmark is yellow

Now in the index.html.en file you'll want to put the following markup

    <img src="check_mark.png" />
    <span>I'm purple because I'm referenced from this current directory</span>

    <img src="/check_mark.png" />
    <span>I'm green because I'm referenced from the ROOT directory</span>

    <img src="subfolder/check_mark.png" />
    <span>I'm yellow because I'm referenced from the child of this current directory</span>

    <img src="/subfolder/check_mark.png" />
    <span>I'm orange because I'm referenced from the child of the ROOT directory</span>

    <img src="../subfolder/check_mark.png" />
    <span>I'm purple because I'm referenced from the parent of this current directory</span>

    <img src="subfolder/subfolder/check_mark.png" />
    <span>I'm [broken] because there is no subfolder two children down from this current directory</span>

    <img src="/subfolder/subfolder/check_mark.png" />
    <span>I'm purple because I'm referenced two children down from the ROOT directory</span>

Now if you load up the index.html.en file located in the second subfolder

This will be your output

enter image description here

Fluid width with equally spaced DIVs


  • This works in IE6+ and all modern browsers!
  • I've halved your requested dimensions just to make it easier to work with.
  • text-align: justify combined with .stretch is what's handling the positioning.
  • display:inline-block; *display:inline; zoom:1 fixes inline-block for IE6/7, see here.
  • font-size: 0; line-height: 0 fixes a minor issue in IE6.

#container {_x000D_
  border: 2px dashed #444;_x000D_
  height: 125px;_x000D_
  text-align: justify;_x000D_
  -ms-text-justify: distribute-all-lines;_x000D_
  text-justify: distribute-all-lines;_x000D_
  /* just for demo */_x000D_
  min-width: 612px;_x000D_
.box4 {_x000D_
  width: 150px;_x000D_
  height: 125px;_x000D_
  vertical-align: top;_x000D_
  display: inline-block;_x000D_
  *display: inline;_x000D_
  zoom: 1_x000D_
.stretch {_x000D_
  width: 100%;_x000D_
  display: inline-block;_x000D_
  font-size: 0;_x000D_
  line-height: 0_x000D_
.box3 {_x000D_
  background: #ccc_x000D_
.box4 {_x000D_
  background: #0ff_x000D_
<div id="container">_x000D_
  <div class="box1"></div>_x000D_
  <div class="box2"></div>_x000D_
  <div class="box3"></div>_x000D_
  <div class="box4"></div>_x000D_
  <span class="stretch"></span>_x000D_

The extra span (.stretch) can be replaced with :after.

This still works in all the same browsers as the above solution. :after doesn't work in IE6/7, but they're using distribute-all-lines anyway, so it doesn't matter.


There's a minor downside to :after: to make the last row work perfectly in Safari, you have to be careful with the whitespace in the HTML.

Specifically, this doesn't work:

<div id="container">
    <div class="box3"></div>
    <div class="box4"></div>

And this does:

<div id="container">
    <div class="box3"></div>
    <div class="box4"></div></div>

You can use this for any arbitrary number of child divs without adding a boxN class to each one by changing

.box1, .box2, .box3, .box4 { ...


#container > div { ...

This selects any div that is the first child of the #container div, and no others below it. To generalize the background colors, you can use the CSS3 nth-order selector, although it's only supported in IE9+ and other modern browsers:

.box1, .box3 { ...


#container > div:nth-child(odd) { ...

See here for a jsfiddle example.

<!--[if !IE]> not working

For IE browser:

<!--[if IE]>
<meta http-equiv="Content-Type" content="text/html; charset=Unicode">

For all non-IE browsers:

<![if !IE]>
<meta http-equiv="Content-Type" content="text/html; charset=utf8">

For all IE greater than 8 OR all non-IE browsers :

<!--[if (gt IE 8)|!(IE)]><!--><script src="/_JS/library/jquery-2.1.1.min.js"></script><!--<![endif]-->

Disable back button in android

If you want to disable your app while logging out, you can pop up a non-cancellable dialog.

How to use paths in tsconfig.json?

You can use combination of baseUrl and paths docs.

Assuming root is on the topmost src dir(and I read your image properly) use

// tsconfig.json
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "lib/*": [

For webpack you might also need to add module resolution. For webpack2 this could look like

// webpack.config.js
module.exports = {
    resolve: {
        modules: [

Good MapReduce examples

From time to time I present MR concepts to people. I find processing tasks familiar to people and then map them to the MR paradigm.

Usually I take two things:

  1. Group By / Aggregations. Here the advantage of the shuffling stage is clear. An explanation that shuffling is also distributed sort + an explanation of distributed sort algorithm also helps.

  2. Join of two tables. People working with DB are familiar with the concept and its scalability problem. Show how it can be done in MR.

Matplotlib legends in subplot

What you want cannot be done, because plt.legend() places a legend in the current axes, in your case in the last one.

If, on the other hand, you can be content with placing a comprehensive legend in the last subplot, you can do like this

f, (ax1, ax2, ax3) = plt.subplots(3, sharex=True, sharey=True)
l1,=ax1.plot(x,y, color='r', label='Blue stars')
l2,=ax2.plot(x,y, color='g')
l3,=ax3.plot(x,y, color='b')
plt.legend([l1, l2, l3],["HHZ 1", "HHN", "HHE"])

enter image description here

Note that you pass to legend not the axes, as in your example code, but the lines as returned by the plot invocation.


Of course you can invoke legend after each subplot, but in my understanding you already knew that and were searching for a method for doing it at once.

Can I have an IF block in DOS batch file?

I ran across this article in the results returned by a search related to the IF command in a batch file, and I couldn't resist the opportunity to correct the misconception that IF blocks are limited to single commands. Following is a portion of a production Windows NT command script that runs daily on the machine on which I am composing this reply.

    if "%COPYTOOL%" equ "R" (
    WWLOGGER.exe "%APPDATA%\WizardWrx\%~n0.LOG" "Using RoboCopy to make a backup of %USERPROFILE%\My Documents\Outlook Files\*"
    %TOOLPATH% %SRCEPATH% %DESTPATH% /copyall %RCLOGSTR% /m /np /r:0 /tee
    C:\BIN\ExitCodeMapper.exe C:\BIN\ExitCodeMapper.INI[Robocopy] %TEMP%\%~n0.TMP %ERRORLEVEL%
) else (
    WWLOGGER.exe "%APPDATA%\WizardWrx\%~n0.LOG" "Using XCopy to make a backup of %USERPROFILE%\My Documents\Outlook Files\*"
    call %TOOLPATH%  "%USERPROFILE%\My Documents\Outlook Files\*" "%USERPROFILE%\My Documents\Outlook Files\_backups" /f /m /v /y
    C:\BIN\ExitCodeMapper.exe C:\BIN\ExitCodeMapper.INI[Xcopy] %TEMP%\%~n0.TMP %ERRORLEVEL%

Perhaps blocks of two or more lines applies exclusively to Windows NT command scripts (.CMD files), because a search of the production scripts directory of an application that is restricted to old school batch (.BAT) files, revealed only one-command blocks. Since the application has gone into extended maintenance (meaning that I am not actively involved in supporting it), I can't say whether that is because I didn't need more than one line, or that I couldn't make them work.

Regardless, if the latter is true, there is a simple workaround; move the multiple lines into either a separate batch file or a batch file subroutine. I know that the latter works in both kinds of scripts.

Get the value of checked checkbox?

Use this:


This assumes the checkboxes to check have the class "messageCheckbox", otherwise you would have to do a check if the input is the checkbox type, etc.

Shortcut to create properties in Visual Studio?

In addition to Amra's answer, you can find other snippets by typing

Ctrl + K, Ctrl + X

Which is mapped to Edit.InsertSnippet in my Visual Studio and shows you the full list of snippets available.

Also remember that you can configure your own snippets by using the Snippets Manager, which is available in the Tools menu, Code Snippets Manager.... Basically you create a file *.snippet and use the Import button in the Code Snippets Manager to add it to Visual Studio. For a full tutorial you can go to the docs; Walkthrough: Create a code snippet.

In Visual Studio Code snippets are handled slightly different than in Visual Studio. You can access all snippets by typing Ctrl + Shift + P and type in snippet. Two options should be available, Insert Snippet and Preferences: Configure User Snippets.

The former inserts a snippet from your list of snippets (using the Language Mode which you can see in the status bar), and with the latter you can create your own snippets for any Language Mode.

If you know the shortname you can just type that and use Tab to expand the snippet. For inserting a C# property you have three snippets available, prop, propfull, and propg, for different purposes.

check all socket opened in linux OS

You can use netstat command

netstat --listen

To display open ports and established TCP connections,

netstat -vatn

To display only open UDP ports try the following command:

netstat -vaun

Python urllib2: Receive JSON response from url

Return JSON to webpage
Adding to wonderful answer by @Sanal
For Django 3.4
Adding a working url that returns a json (Source:

import json
import urllib

url = ''
respons = urllib.request.urlopen(url)
data = json.loads('charset') or 'utf-8'))
return HttpResponse(json.dumps(data), content_type="application/json")

Quick way to retrieve user information Active Directory

Well, if you know where your user lives in the AD hierarchy (e.g. quite possibly in the "Users" container, if it's a small network), you could also bind to the user account directly, instead of searching for it.

DirectoryEntry deUser = new DirectoryEntry("LDAP://cn=John Doe,cn=Users,dc=yourdomain,dc=com");

if (deUser != null)
  ... do something with your user

And if you're on .NET 3.5 already, you could even use the vastly expanded System.DirectorySrevices.AccountManagement namespace with strongly typed classes for each of the most common AD objects:

// bind to your domain
PrincipalContext pc = new PrincipalContext(ContextType.Domain, "LDAP://dc=yourdomain,dc=com");

// find the user by identity (or many other ways)
UserPrincipal user = UserPrincipal.FindByIdentity(pc, "cn=John Doe");

There's loads of information out there on System.DirectoryServices.AccountManagement - check out this excellent article on MSDN by Joe Kaplan and Ethan Wilansky on the topic.

Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?

In many applications, like MsOffice (until version 2000 or 2002), the maximum number of characters per cell was 255. Moving data from programs able of handling more than 255 characters per field to/from those applications was a nightmare. Currently, the limit is less and less hindering.

Get first day of week in SQL Server

I found this simple and usefull. Works even if first day of week is Sunday or Monday.

DECLARE @BaseDate AS Date

SET @BaseDate = GETDATE()


SELECT @FirstDOW = DATEADD(d,DATEPART(WEEKDAY,@BaseDate) *-1 + 1, @BaseDate)

Best practice to run Linux service as a different user

On Debian we use the start-stop-daemon utility, which handles pid-files, changing the user, putting the daemon into background and much more.

I'm not familiar with RedHat, but the daemon utility that you are already using (which is defined in /etc/init.d/functions, btw.) is mentioned everywhere as the equivalent to start-stop-daemon, so either it can also change the uid of your program, or the way you do it is already the correct one.

If you look around the net, there are several ready-made wrappers that you can use. Some may even be already packaged in RedHat. Have a look at daemonize, for example.

EditText onClickListener in Android

As Dillon Kearns suggested, setting focusable to false works fine. But if your goal is to cancel the keyboard when EditText is clicked, you might want to use:


Create a temporary table in MySQL with an index from a select

I wrestled quite a while with the proper syntax for CREATE TEMPORARY TABLE SELECT. Having figured out a few things, I wanted to share the answers with the rest of the community.

Basic information about the statement is available at the following MySQL links:


At times it can be daunting to interpret the spec. Since most people learn best from examples, I will share how I have created a working statement, and how you can modify it to work for you.

  1. Add multiple indexes

    This statement shows how to add multiple indexes (note that index names - in lower case - are optional):

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (INDEX my_index_name (tag, time), UNIQUE my_unique_index_name (order_number))
    SELECT * FROM core.my_big_table
    WHERE my_val = 1
  2. Add a new primary key:

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (PRIMARY KEY my_pkey (order_number),
    INDEX cmpd_key (user_id, time))
    SELECT * FROM core.my_big_table
  3. Create additional columns

    You can create a new table with more columns than are specified in the SELECT statement. Specify the additional column in the table definition. Columns specified in the table definition and not found in select will be first columns in the new table, followed by the columns inserted by the SELECT statement.

    CREATE TEMPORARY TABLE core.my_tmp_table 
    PRIMARY KEY my_pkey (my_new_id), INDEX my_unique_index_name (invoice_number))
    SELECT * FROM core.my_big_table
  4. Redefining data types for the columns from SELECT

    You can redefine the data type of a column being SELECTed. In the example below, column tag is a MEDIUMINT in core.my_big_table and I am redefining it to a BIGINT in core.my_tmp_table.

    CREATE TEMPORARY TABLE core.my_tmp_table 
    (tag BIGINT,
    my_time DATETIME,  
    INDEX my_unique_index_name (tag) )
    SELECT * FROM core.my_big_table
  5. Advanced field definitions during create

    All the usual column definitions are available as when you create a normal table. Example:

    CREATE TEMPORARY TABLE core.my_tmp_table 
    country CHAR(2) DEFAULT "XX" COMMENT "Two-letter country code",  
    INDEX my_index_name (location))
    SELECT * FROM core.my_big_table

Very simple C# CSV reader

This fixed version of code above remember the last element of CVS row ;-)

(tested with a CSV file with 5400 rows and 26 elements by row)

   public static string[] CSVRowToStringArray(string r, char fieldSep = ',', char stringSep = '\"')  {
            bool bolQuote = false;
            StringBuilder bld = new StringBuilder();
            List<string> retAry = new List<string>();

            foreach (char c in r.ToCharArray())
                if ((c == fieldSep && !bolQuote))
                    if (c == stringSep)
                        bolQuote = !bolQuote;

            /* to solve the last element problem */
            retAry.Add(bld.ToString()); /* added this line */
            return retAry.ToArray();

Getting all selected checkboxes in an array

here is my code for the same problem someone can also try this. jquery

var favorite1 = [];        
$.each($("input[name='check1']:checked"), function(){                    

angularjs getting previous route path

In your html :

<a href="javascript:void(0);" ng-click="go_back()">Go Back</a>

On your main controller :

$scope.go_back = function() { 

When user click on Go Back link the controller function is called and it will go back to previous route.

CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default

I found that the direct cause for the error in my case was:

build -> advanced -> language version

this makes sense since the error is stating that there is an invalid option for language.

but, this was working fine before - so it must've been selected. what changed? turns out a member on my team upgraded to vs 2017, while i was still using 2015. after he made changes to the project, the language version was changed and i received that change over source control. but the version selected was not available to my version of vs, so it was blank - hence the error. after selecting a value in the language drop down (i chose default), a new error popped up. the new error was causing a build failure on any lines of code which used the newer version of c#. i changed the code to perform the same functions, but with my c# version syntax and problem solved.

so while the direct cause of the error was indeed an invalid selection of Language Version, the root cause was due to different vs/c# versions conflicting.

Count rows with not empty value

Make another column that determines if the referenced cell is blank using the function "CountBlank". Then use count on the values created in the new "CountBlank" column.

Insertion Sort vs. Selection Sort

Selection Sort:

Given a list, take the current element and exchange it with the smallest element on the right hand side of the current element. Selection Sort

Insertion Sort:

Given a list, take the current element and insert it at the appropriate position of the list, adjusting the list every time you insert. It is similar to arranging the cards in a Card game. Insertion Sort

Time Complexity of selection sort is always n(n - 1)/2, whereas insertion sort has better time complexity as its worst case complexity is n(n - 1)/2. Generally it will take lesser or equal comparisons then n(n - 1)/2.


Fetching distinct values on a column using Spark DataFrame

This solution demonstrates how to transform data with Spark native functions which are better than UDFs. It also demonstrates how dropDuplicates which is more suitable than distinct for certain queries.

Suppose you have this DataFrame:

|country|    continent|
|  china|         asia|
| brazil|south america|
| france|       europe|
|  china|         asia|

Here's how to take all the distinct countries and run a transformation:

  .withColumn("country", concat(col("country"), lit(" is fun!")))
|       country|
|brazil is fun!|
|france is fun!|
| china is fun!|

You can use dropDuplicates instead of distinct if you don't want to lose the continent information:

  .withColumn("description", concat(col("country"), lit(" is a country in "), col("continent")))
|country|continent    |description                         |
|brazil |south america|brazil is a country in south america|
|france |europe       |france is a country in europe       |
|china  |asia         |china is a country in asia          |

See here for more information about filtering DataFrames and here for more information on dropping duplicates.

Ultimately, you'll want to wrap your transformation logic in custom transformations that can be chained with the Dataset#transform method.

Deleting an object in java?

You can remove the reference using null.

Let's say You have class A:

A a = new A();

last statement will remove the reference of the object a and that object will be "garbage collected" by JVM. It is one of the easiest ways to do this.

Java method to sum any number of ints

If your using Java8 you can use the IntStream:

int[] listOfNumbers = {5,4,13,7,7,8,9,10,5,92,11,3,4,2,1};

Results: 181

Just 1 line of code which will sum the array.

SQL: parse the first, middle and last name from a fullname field

  1. Get a sql regex function. Sample:
  2. Extract names using regular expressions.

I recommend Expresso for learnin/building/testing regular expressions. Old free version, new commercial version

JPA or JDBC, how are they different?

In layman's terms:

  • JDBC is a standard for Database Access
  • JPA is a standard for ORM

JDBC is a standard for connecting to a DB directly and running SQL against it - e.g SELECT * FROM USERS, etc. Data sets can be returned which you can handle in your app, and you can do all the usual things like INSERT, DELETE, run stored procedures, etc. It is one of the underlying technologies behind most Java database access (including JPA providers).

One of the issues with traditional JDBC apps is that you can often have some crappy code where lots of mapping between data sets and objects occur, logic is mixed in with SQL, etc.

JPA is a standard for Object Relational Mapping. This is a technology which allows you to map between objects in code and database tables. This can "hide" the SQL from the developer so that all they deal with are Java classes, and the provider allows you to save them and load them magically. Mostly, XML mapping files or annotations on getters and setters can be used to tell the JPA provider which fields on your object map to which fields in the DB. The most famous JPA provider is Hibernate, so it's a good place to start for concrete examples.

Other examples include OpenJPA, toplink, etc.

Under the hood, Hibernate and most other providers for JPA write SQL and use JDBC to read and write from and to the DB.

Is there any way to configure multiple registries in a single npmrc file

You can have multiple registries for scoped packages in your .npmrc file. For example:

@polymer:registry=<url register A>

Packages under @polymer scope will be received from, but the rest will be received from your local NPM.

Are querystring parameters secure in HTTPS (HTTP + SSL)?

The entire transmission, including the query string, the whole URL, and even the type of request (GET, POST, etc.) is encrypted when using HTTPS.

File to import not found or unreadable: compass

I'm seeing this issue using Rails 4.0.2 and compass-rails 1.1.3

I got past this error by moving gem 'compass-rails' outside of the :assets group in my Gemfile

It looks something like this:

# stuff
gem 'compass-rails', '~> 1.1.3'
group :assets do
  # more stuff

How to write a shell script that runs some commands as superuser and some commands not as superuser, without having to babysit it?

If you use this, check man sudo too:


sudo echo "Hi, I'm root"

sudo -u nobody echo "I'm nobody"

sudo -u 1000 touch /test_user

How to Set the Background Color of a JButton on the Mac OS

I own a mac too! here is the code that will work:

myButton.setOpaque(true); //Sets Button Opaque so it works

before doing anything or adding any components set the look and feel so it looks better:

 }catch(Exception e){

That is Supposed to change the look and feel to the cross platform look and feel, hope i helped! :)

Angular.js and HTML5 date input value -- how to get Firefox to show a readable date value in a date input?

Check this fully functional directive for MEAN.JS (Angular.js, bootstrap, Express.js and MongoDb)

Based on @Blackhole ´s response, we just finished it to be used with mongodb and express.

It will allow you to save and load dates from a mongoose connector

Hope it Helps!!

  function(dateFilter) {
    return {
      require: 'ngModel',
      template: '<input type="date" class="form-control"></input>',
      replace: true,
      link: function(scope, elm, attrs, ngModelCtrl) {
        ngModelCtrl.$formatters.unshift(function (modelValue) {
          return dateFilter(modelValue, 'yyyy-MM-dd');

           return angular.toJson(modelValue,true)



div(date-input, ng-model="modelDate")

How to fix "containing working copy admin area is missing" in SVN?

First of all checkout the project into your system in a folder. Then remove the .svn folder from conflict project and copy the .svn folder from new checkout folder and paste into your working copy folder. Then problem is solved.

laravel throwing MethodNotAllowedHttpException

well when i had these problem i faced 2 code errors

{!! Form::model(['method' => 'POST','route' => ['']]) !!}

i corrected it by doing this

{!! Form::open(['method' => 'POST','route' => '']) !!}

so just to expatiate i changed the form model to open and also the route where wrongly placed in square braces.

How do I convert an array object to a string in PowerShell?

$a = 'This', 'Is', 'a', 'cat'

Using double quotes (and optionally use the separator $ofs)

# This Is a cat

# This-Is-a-cat
$ofs = '-' # after this all casts work this way until $ofs changes!

Using operator join

# This-Is-a-cat
$a -join '-'

# ThisIsacat
-join $a

Using conversion to [string]

# This Is a cat

# This-Is-a-cat
$ofs = '-'

"Stack overflow in line 0" on Internet Explorer

You can turn off the "Disable Script Debugging" option inside of Internet Explorer and start debugging with Visual Studio if you happen to have that around.

I've found that it is one of few ways to diagnose some of those IE specific issues.

Chrome hangs after certain amount of data transfered - waiting for available socket

simple and correct solution is put off preload your audio and video file from setting and recheck your page your problem of waiting for available socket will resolved ...

if you use jplayer then replace preload:"metadata" to preload:"none" from jplayer JS file ...

preload:"metadata" is the default value which play your audio/video file on page load thats why google chrome showing "waiting for available socket" error

grep from tar.gz without extracting [faster one]

All of the code above was really helpful, but none of it quite answered my own need: grep all *.tar.gz files in the current directory to find a pattern that is specified as an argument in a reusable script to output:

  • The name of both the archive file and the extracted file
  • The line number where the pattern was found
  • The contents of the matching line

It's what I was really hoping that zgrep could do for me and it just can't.

Here's my solution:

for f in *.tar.gz; do
     echo "$f:"
     tar -xzf "$f" --to-command 'grep --label="`basename $TAR_FILENAME`" -Hin '"$pattern ; true";

You can also replace the tar line with the following if you'd like to test that all variables are expanding properly with a basic echo statement:

tar -xzf "$f" --to-command 'echo "f:`basename $TAR_FILENAME` s:'"$pattern\""

Let me explain what's going on. Hopefully, the for loop and the echo of the archive filename in question is obvious.

tar -xzf: x extract, z filter through gzip, f based on the following archive file...

"$f": The archive file provided by the for loop (such as what you'd get by doing an ls) in double-quotes to allow the variable to expand and ensure that the script is not broken by any file names with spaces, etc.

--to-command: Pass the output of the tar command to another command rather than actually extracting files to the filesystem. Everything after this specifies what the command is (grep) and what arguments we're passing to that command.

Let's break that part down by itself, since it's the "secret sauce" here.

'grep --label="`basename $TAR_FILENAME`" -Hin '"$pattern ; true"

First, we use a single-quote to start this chunk so that the executed sub-command (basename $TAR_FILENAME) is not immediately expanded/resolved. More on that in a moment.

grep: The command to be run on the (not actually) extracted files

--label=: The label to prepend the results, the value of which is enclosed in double-quotes because we do want to have the grep command resolve the $TAR_FILENAME environment variable passed in by the tar command.

basename $TAR_FILENAME: Runs as a command (surrounded by backticks) and removes directory path and outputs only the name of the file

-Hin: H Display filename (provided by the label), i Case insensitive search, n Display line number of match

Then we "end" the first part of the command string with a single quote and start up the next part with a double quote so that the $pattern, passed in as the first argument, can be resolved.

Realizing which quotes I needed to use where was the part that tripped me up the longest. Hopefully, this all makes sense to you and helps someone else out. Also, I hope I can find this in a year when I need it again (and I've forgotten about the script I made for it already!)

And it's been a bit a couple of weeks since I wrote the above and it's still super useful... but it wasn't quite good enough as files have piled up and searching for things has gotten more messy. I needed a way to limit what I looked at by the date of the file (only looking at more recent files). So here's that code. Hopefully it's fairly self-explanatory.

if [ -z "$1" ]; then
    echo "Look within all tar.gz files for a string pattern, optionally only in recent files"
    echo "Usage: targrep <string to search for> [start date]"
startdate=$(date -d "$startdatein" +%s)
for f in *.tar.gz; do
    filedate=$(date -r "$f" +%s)
    if [[ -z "$startdatein" ]] || [[ $filedate -ge $startdate ]]; then
        echo "$f:"
        tar -xzf "$f" --to-command 'grep --label="`basename $TAR_FILENAME`" -Hin '"$pattern ; true"

And I can't stop tweaking this thing. I added an argument to filter by the name of the output files in the tar file. Wildcards work, too.

Usage: [-d <start date>] [-f <filename to include>] <string to search for>

Example: -d "1/1/2019" -f "*vehicle_models.csv" ford

while getopts "d:f:" opt; do
    case $opt in
            d) startdatein=$OPTARG;;
            f) targetfile=$OPTARG;;
shift "$((OPTIND-1))" # Discard options and bring forward remaining arguments

echo "Searching for: $pattern"
if [[ -n $targetfile ]]; then
    echo "in filenames:  $targetfile"

startdate=$(date -d "$startdatein" +%s)
for f in *.tar.gz; do
    filedate=$(date -r "$f" +%s)
    if [[ -z "$startdatein" ]] || [[ $filedate -ge $startdate ]]; then
            echo "$f:"
            if [[ -z "$targetfile" ]]; then
                    tar -xzf "$f" --to-command 'grep --label="`basename $TAR_FILENAME`" -Hin '"$pattern ; true"
                    tar -xzf "$f" --no-anchored "$targetfile" --to-command 'grep --label="`basename $TAR_FILENAME`" -Hin '"$pattern ; true"

design a stack such that getMinimum( ) should be O(1)

class FastStack {

    private static class StackNode {
        private Integer data;
        private StackNode nextMin;

        public StackNode(Integer data) {
   = data;

        public Integer getData() {
            return data;

        public void setData(Integer data) {
   = data;

        public StackNode getNextMin() {
            return nextMin;

        public void setNextMin(StackNode nextMin) {
            this.nextMin = nextMin;


    private LinkedList<StackNode> stack = new LinkedList<>();

    private StackNode currentMin = null;

    public void push(Integer item) {
        StackNode node = new StackNode(item);
        if (currentMin == null) {
            currentMin = node;
        } else if (item < currentMin.getData()) {
            StackNode oldMinNode = currentMin;
            currentMin = node;


    public Integer pop() {
        if (stack.isEmpty()) {
            throw new EmptyStackException();
        StackNode node = stack.peek();
        if (currentMin == node) {
            currentMin = node.getNextMin();
        return node.getData();

    public Integer getMinimum() {
        if (stack.isEmpty()) {
            throw new NoSuchElementException("Stack is empty");
        return currentMin.getData();

how to configuring a xampp web server for different root directory

ok guys you are not going to believe me how easy it is, so i putted a video on YouTube to show you that [ click here ]

now , steps :

  1. run your xampp control panel
  2. click the button saying config
  3. select apache( httpd.conf )
  4. find document root
  5. replace

DocumentRoot "C:/xampp/htdocs" <Directory "C:/xampp/htdocs">

those 2 lines || C:/xampp/htdocs == current location for root || change C:/xampp/htdocs with any location you want

  1. save it DONE: start apache and go to the localhost see in action [ watch video click here ]

Do you have to put Task.Run in a method to make it async?

When you use Task.Run to run a method, Task gets a thread from threadpool to run that method. So from the UI thread's perspective, it is "asynchronous" as it doesn't block UI thread.This is fine for desktop application as you usually don't need many threads to take care of user interactions.

However, for web application each request is serviced by a thread-pool thread and thus the number of active requests can be increased by saving such threads. Frequently using threadpool threads to simulate async operation is not scalable for web applications.

True Async doesn't necessarily involving using a thread for I/O operations, such as file / DB access etc. You can read this to understand why I/O operation doesn't need threads.

In your simple example,it is a pure CPU-bound calculation, so using Task.Run is fine.

Create stacked barplot where each stack is scaled to sum to 100%

Chris Beeley is rigth, you only need the proportions by column. Using your data is:


 barplot(prop.table(your_matrix, 2) )


enter image description here

Java character array initializer

You initialized and declared your String to "Hi there", initialized your char[] array with the correct size, and you began a loop over the length of the array which prints an empty string combined with a given element being looked at in the array. At which point did you factor in the functionality to put in the characters from the String into the array?

When you attempt to print each element in the array, you print an empty String, since you're adding 'nothing' to an empty String, and since there was no functionality to add in the characters from the input String to the array. You have everything around it correctly implemented, though. This is the code that should go after you initialize the array, but before the for-loop that iterates over the array to print out the elements.

for (int count = 0; count < ini.length(); count++) {
  array[count] = ini.charAt(count);

It would be more efficient to just combine the for-loops to print each character out right after you put it into the array.

for (int count = 0; count < ini.length(); count++) {
  array[count] = ini.charAt(count);

At this point, you're probably wondering why even put it in a char[] when I can just print them using the reference to the String object ini itself.

String ini = "Hi there";

for (int count = 0; count < ini.length(); count++) {

Definitely read about Java Strings. They're fascinating and work pretty well, in my opinion. Here's a decent link:

String ini = "Hi there"; // stored in String constant pool

is stored differently in memory than

String ini = new String("Hi there"); // stored in heap memory and String constant pool

, which is stored differently than

char[] inichar = new char[]{"H", "i", " ", "t", "h", "e", "r", "e"};
String ini = new String(inichar); // converts from char array to string


Change the content of a div based on selection from dropdown menu

There are many ways to perform your task, but the most elegant are, I believe, using css. Here are basic steps

  1. Listening option selection event, biding adding/removing some class to container action, which contains all divs you are interested in (for example, body)
  2. Adding styles for hiding all divs except one.
  3. Well done, sir.

This works pretty well if there a few divs, since more elements you want to toggle, more css rules should be written. Here is more general solution, binding action, base on following steps: 1. find all elements using some selector (usually it looks like '.menu-container .menu-item') 2. find one of found elements, which is current visible, hide it 3. make visible another element, the one you desire to be visible under new circumstances.

javascript it a rather timtoady language )

How do I access ViewBag from JS

ViewBag is server side code.
Javascript is client side code.

You can't really connect them.

You can do something like this:

var x = $('#' + '@(ViewBag.CC)').val();

But it will get parsed on the server, so you didn't really connect them.

Instantiating a generic class in Java

And this is the Factory implementation, as Jon Skeet suggested:

interface Factory<T> {
    T factory();

class Araba {
    //static inner class for Factory<T> implementation
    public static class ArabaFactory implements Factory<Araba> {
        public Araba factory() {
            return new Araba();
    public String toString() { return "Abubeee"; }

class Generic<T> {
    private T var;

    Generic(Factory<T> fact) {
        System.out.println("Constructor with Factory<T> parameter");
        var = fact.factory();
    Generic(T var) {
        System.out.println("Constructor with T parameter");
        this.var = var;
    T get() { return var; }

public class Main {
    public static void main(String[] string) {
        Generic<Araba> gen = new Generic<Araba>(new Araba.ArabaFactory());


Constructor with Factory<T> parameter

"Unable to locate tools.jar" when running ant

  1. Try to check it once more according to this tutorial:

  2. Try to reboot your system.

  3. If nothing, try to run "cmd" and type there "java", does it print anything?

LaTeX "\indent" creating paragraph indentation / tabbing package requirement?

LaTeX will usually not indent the first paragraph of a section. This is standard typographical practice. However, if you really want to override this default setting, use the package indentfirst available on CTAN.

Is Android using NTP to sync time?

I have a Samsung Galaxy Tab 2 7.0 with Android 4.1.1. Apparently it does NOT sync to ntp. I loaded an app that says my tablet is 20 seconds off of ntp, but it can't set it unless I root the device.


When the propagation setting is PROPAGATION_REQUIRED, a logical transaction scope is created for each method upon which the setting is applied. Each such logical transaction scope can determine rollback-only status individually, with an outer transaction scope being logically independent from the inner transaction scope. Of course, in case of standard PROPAGATION_REQUIRED behavior, all these scopes will be mapped to the same physical transaction. So a rollback-only marker set in the inner transaction scope does affect the outer transaction's chance to actually commit (as you would expect it to).

enter image description here

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

From wiki page

12 (form feed, \f, ^L), to cause a printer to eject paper to the top of the next page, or a video terminal to clear the screen.

or more details here.

It seems that this symbol is rather obsolete now and the way it is processed may be(?) implementation dependent. At least for me your code gives the following output (xcode gcc 4.2, gdb console):


Submit button doesn't work

Hello from the future.

For clarity, I just wanted to add (as this was pretty high up in google) - we can now use

<button type="submit">Upload Stuff</button>

And to reset a form

<button type="reset" value="Reset">Reset</button>

Check out button types

We can also attach buttons to submit forms like this:

<button type="submit" form="myform" value="Submit">Submit</button>

TypeError: unhashable type: 'dict', when dict used as a key for another dict

From the error, I infer that referenceElement is a dictionary (see repro below). A dictionary cannot be hashed and therefore cannot be used as a key to another dictionary (or itself for that matter!).

>>> d1, d2 = {}, {}
>>> d1[d2] = 1
Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: unhashable type: 'dict'

You probably meant either for element in referenceElement.keys() or for element in json['referenceElement'].keys(). With more context on what types json and referenceElement are and what they contain, we will be able to better help you if neither solution works.

How to sort List<Integer>?

Just use Collections.sort(yourListHere) here to sort.

You can read more about Collections from here.

HTML 5 Favicon - Support?

The answers provided (at the time of this post) are link only answers so I thought I would summarize the links into an answer and what I will be using.

When working to create Cross Browser Favicons (including touch icons) there are several things to consider.

The first (of course) is Internet Explorer. IE does not support PNG favicons until version 11. So our first line is a conditional comment for favicons in IE 9 and below:

<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

To cover the uses of the icon create it at 32x32 pixels. Notice the rel="shortcut icon" for IE to recognize the icon it needs the word shortcut which is not standard. Also we wrap the .ico favicon in a IE conditional comment because Chrome and Safari will use the .ico file if it is present, despite other options available, not what we would like.

The above covers IE up to IE 9. IE 11 accepts PNG favicons, however, IE 10 does not. Also IE 10 does not read conditional comments thus IE 10 won't show a favicon. With IE 11 and Edge available I don't see IE 10 in widespread use, so I ignore this browser.

For the rest of the browsers we are going to use the standard way to cite a favicon:

<link rel="icon" href="path/to/favicon.png">

This icon should be 196x196 pixels in size to cover all devices that may use this icon.

To cover touch icons on mobile devices we are going to use Apple's proprietary way to cite a touch icon:

<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

Using rel="apple-touch-icon-precomposed" will not apply the reflective shine when bookmarked on iOS. To have iOS apply the shine use rel="apple-touch-icon". This icon should be sized to 180x180 pixels as that is the current size recommend by Apple for the latest iPhones and iPads. I have read Blackberry will also use rel="apple-touch-icon-precomposed".

As a note: Chrome for Android states:

The apple-touch-* are deprecated, and will be supported only for a short time. (Written as of beta for m31 of Chrome).

Custom Tiles for IE 11+ on Windows 8.1+

IE 11+ on Windows 8.1+ does offer a way to create pinned tiles for your site.

Microsoft recommends creating a few tiles at the following size:

Small: 128 x 128

Medium: 270 x 270

Wide: 558 x 270

Large: 558 x 558

These should be transparent images as we will define a color background next.

Once these images are created you should create an xml file called browserconfig.xml with the following code:

<?xml version="1.0" encoding="utf-8"?>
      <square70x70logo src="images/smalltile.png"/>
      <square150x150logo src="images/mediumtile.png"/>
      <wide310x150logo src="images/widetile.png"/>
      <square310x310logo src="images/largetile.png"/>

Save this xml file in the root of your site. When a site is pinned IE will look for this file. If you want to name the xml file something different or have it in a different location add this meta tag to the head:

<meta name="msapplication-config" content="path-to-browserconfig/custom-name.xml" />

For additional information on IE 11+ custom tiles and using the XML file visit Microsoft's website.

Putting it all together:

To put it all together the above code would look like this:

<!-- For IE 9 and below. ICO should be 32x32 pixels in size -->
<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

<!-- Touch Icons - iOS and Android 2.1+ 180x180 pixels in size. --> 
<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

<!-- Firefox, Chrome, Safari, IE 11+ and Opera. 196x196 pixels in size. -->
<link rel="icon" href="path/to/favicon.png">

Windows Phone Live Tiles

If a user is using a Windows Phone they can pin a website to the start screen of their phone. Unfortunately, when they do this it displays a screenshot of your phone, not a favicon (not even the MS specific code referenced above). To make a "Live Tile" for Windows Phone Users for your website one must use the following code:

Here are detailed instructions from Microsoft but here is a synopsis:

Step 1

Create a square image for your website, to support hi-res screens create it at 768x768 pixels in size.

Step 2

Add a hidden overlay of this image. Here is example code from Microsoft:

<div id="TileOverlay" onclick="ToggleTileOverlay()" style='background-color: Highlight; height: 100%; width: 100%; top: 0px; left: 0px; position: fixed; color: black; visibility: hidden'>
  <img src="customtile.png" width="320" height="320" />
  <div style='margin-top: 40px'>
     Add text/graphic asking user to pin to start using the menu...

Step 3

You then can add thew following line to add a pin to start link:

<a href="javascript:ToggleTileOverlay()">Pin this site to your start screen</a>

Microsoft recommends that you detect windows phone and only show that link to those users since it won't work for other users.

Step 4

Next you add some JS to toggle the overlay visibility

function ToggleTileOverlay() {
 var newVisibility =     (document.getElementById('TileOverlay').style.visibility == 'visible') ? 'hidden' : 'visible';
 document.getElementById('TileOverlay').style.visibility =    newVisibility;

Note on Sizes

I am using one size as every browser will scale down the image as necessary. I could add more HTML to specify multiple sizes if desired for those with a lower bandwidth but I am already compressing the PNG files heavily using TinyPNG and I find this unnecessary for my purposes. Also, according to philippe_b's answer Chrome and Firefox have bugs that cause the browser to load all sizes of icons. Using one large icon may be better than multiple smaller ones because of this.

Further Reading

For those who would like more details see the links below:

How to search in an array with preg_match?

You can use array_walk to apply your preg_match function to each element of the array.

Override intranet compatibility mode IE8

If you want your Web site to force IE 8 standards mode, then use this metatag along with a valid DOCTYPE:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />

Note the "EmulateIE8" value rather than the plain "IE8".

According to IE devs, this should, "Display Standards DOCTYPEs in IE8 Standards mode; Display Quirks DOCTYPEs in Quirks mode. Use this tag to override compatibility view on client machines and force Standards to IE8 Standards."

more info on this IE blog post:

Capturing Groups From a Grep RegEx

A suggestion for you - you can use parameter expansion to remove the part of the name from the last underscore onwards, and similarly at the start:


Then name will have the value abc.

See Apple developer docs, search forward for 'Parameter Expansion'.

Python: Convert timedelta to int in a dataframe

You could do this, where td is your series of timedeltas. The division converts the nanosecond deltas into day deltas, and the conversion to int drops to whole days.

import numpy as np

(td / np.timedelta64(1, 'D')).astype(int)

Clear variable in python

What's wrong with self.left = None?

PHP: How to remove all non printable characters in a string?

Many of the other answers here do not take into account unicode characters (e.g. öäüß??îû??????? ). In this case you can use the following:

$string = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\x9F]/u', '', $string);

There's a strange class of characters in the range \x80-\x9F (Just above the 7-bit ASCII range of characters) that are technically control characters, but over time have been misused for printable characters. If you don't have any problems with these, then you can use:

$string = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]/u', '', $string);

If you wish to also strip line feeds, carriage returns, tabs, non-breaking spaces, and soft-hyphens, you can use:

$string = preg_replace('/[\x00-\x1F\x7F-\xA0\xAD]/u', '', $string);

Note that you must use single quotes for the above examples.

If you wish to strip everything except basic printable ASCII characters (all the example characters above will be stripped) you can use:

$string = preg_replace( '/[^[:print:]]/', '',$string);

For reference see

Echoing the last command run in Bash?

history | tail -2 | head -1 | cut -c8-999

tail -2 returns the last two command lines from history head -1 returns just first line cut -c8-999 returns just command line, removing PID and spaces.

How to find a value in an array of objects in JavaScript?

If you have an array such as

var people = [
  { "name": "bob", "dinner": "pizza" },
  { "name": "john", "dinner": "sushi" },
  { "name": "larry", "dinner": "hummus" }

You can use the filter method of an Array object:

people.filter(function (person) { return person.dinner == "sushi" });
  // => [{ "name": "john", "dinner": "sushi" }]

In newer JavaScript implementations you can use a function expression:

people.filter(p => p.dinner == "sushi")
  // => [{ "name": "john", "dinner": "sushi" }]

You can search for people who have "dinner": "sushi" using a map (person) {
  if (person.dinner == "sushi") {
    return person
  } else {
    return null
}); // => [null, { "name": "john", "dinner": "sushi" }, null]

or a reduce

people.reduce(function (sushiPeople, person) {
  if (person.dinner == "sushi") {
    return sushiPeople.concat(person);
  } else {
    return sushiPeople
}, []); // => [{ "name": "john", "dinner": "sushi" }]

I'm sure you are able to generalize this to arbitrary keys and values!

postgresql: INSERT INTO ... (SELECT * ...)

insert into TABLENAMEA (A,B,C,D) 
select A::integer,B,C,D from TABLENAMEB

Regex pattern inside SQL Replace function?

Here is a function I wrote to accomplish this based off of the previous answers.

CREATE FUNCTION dbo.RepetitiveReplace
    @P_String VARCHAR(MAX),
    @P_Pattern VARCHAR(MAX),
    @P_ReplaceString VARCHAR(MAX),
    @P_ReplaceLength INT = 1
    DECLARE @Index INT;

    -- Get starting point of pattern
    SET @Index = PATINDEX(@P_Pattern, @P_String);

    while @Index > 0
        --replace matching charactger at index
        SET @P_String = STUFF(@P_String, PATINDEX(@P_Pattern, @P_String), @P_ReplaceLength, @P_ReplaceString);
        SET @Index = PATINDEX(@P_Pattern, @P_String);

    RETURN @P_String;



Originally I had a recursive function here which does not play well with sql server as it has a 32 nesting level limit which would result in an error like the below any time you attempt to make 32+ replacements with the function. Instead of trying to make a server level change to allow more nesting (which could be dangerous like allow never ending loops) switching to a while loop makes a lot more sense.

Maximum stored procedure, function, trigger, or view nesting level exceeded (limit 32).

Linux command to check if a shell script is running or not

The solutions above are great for interactive use, where you can eyeball the result and weed out false positives that way.

False positives can occur if the executable itself happens to match, or any arguments that are not script names match - the likelihood is greater with scripts that have no filename extensions.

Here's a more robust solution for scripting, using a shell function:

getscript() {
  pgrep -lf ".[ /]$1( |\$)"

Example use:

# List instance(s) of script "" that are running.
getscript ""  # -> (e.g.): 96112 bash /Users/jdoe/

# Use in a test:
if getscript "" >/dev/null; then
  echo RUNNING
  • Matching is case-sensitive (on macOS, you could add -i to the pgrep call to make it case-insensitive; on Linux, that is not an option.)
  • The getscript function also works with full or partial paths that include the filename component; partial paths must not start with / and each component specified must be complete. The "fuller" the path specified, the lower the risk of false positives. Caveat: path matching will only work if the script was invoked with a path - this is generally true for scripts in the $PATH that are invoked directly.
  • Even this function cannot rule out all false positives, as paths can have embedded spaces, yet neither ps nor pgrep reflect the original quoting applied to the command line. All the function guarantees is that any match is not the first token (which is the interpreter), and that it occurs as a separate word, optionally preceded by a path.
  • Another approach to minimizing the risk of false positives could be to match the executable name (i.e., interpreter, such as bash) as well - assuming it is known; e.g.
# List instance(s) of a running *bash* script.
getbashscript() {
  pgrep -lf "(^|/)bash( | .*/)$1( |\$)"

If you're willing to make further assumptions - such as script-interpreter paths never containing embedded spaces - the regexes could be made more restrictive and thus further reduce the risk of false positives.

How to animate a View with Translate Animation in Android

In order to move a View anywhere on the screen, I would recommend placing it in a full screen layout. By doing so, you won't have to worry about clippings or relative coordinates.

You can try this sample code:


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android=""
    android:orientation="vertical" android:id="@+id/rootLayout">

        android:text="MOVE" android:layout_centerHorizontal="true"/>

        android:src="@drawable/ic_launcher" android:layout_marginLeft="10dip"/>
        android:src="@drawable/ic_launcher" android:layout_centerVertical="true" android:layout_alignParentRight="true"/>
        android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_alignParentBottom="true" android:layout_marginBottom="100dip"/>

        android:orientation="vertical" android:clipChildren="false" android:clipToPadding="false">

            android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_marginTop="150dip"/>


Your activity

public void onCreate(Bundle savedInstanceState) {

    ((Button) findViewById( )).setOnClickListener( new OnClickListener()
        public void onClick(View v)
            ImageView img = (ImageView) findViewById( );              
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( );
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( );                
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( );
            moveViewToScreenCenter( img );

private void moveViewToScreenCenter( View view )
    RelativeLayout root = (RelativeLayout) findViewById( );
    DisplayMetrics dm = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics( dm );
    int statusBarOffset = dm.heightPixels - root.getMeasuredHeight();

    int originalPos[] = new int[2];
    view.getLocationOnScreen( originalPos );

    int xDest = dm.widthPixels/2;
    xDest -= (view.getMeasuredWidth()/2);
    int yDest = dm.heightPixels/2 - (view.getMeasuredHeight()/2) - statusBarOffset;

    TranslateAnimation anim = new TranslateAnimation( 0, xDest - originalPos[0] , 0, yDest - originalPos[1] );
    anim.setFillAfter( true );

The method moveViewToScreenCenter gets the View's absolute coordinates and calculates how much distance has to move from its current position to reach the center of the screen. The statusBarOffset variable measures the status bar height.

I hope you can keep going with this example. Remember that after the animation your view's position is still the initial one. If you tap the MOVE button again and again the same movement will repeat. If you want to change your view's position do it after the animation is finished.

Git push existing repo to a new and different remote repo server?

  1. Create a new repo at github.
  2. Clone the repo from fedorahosted to your local machine.
  3. git remote rename origin upstream
  4. git remote add origin URL_TO_GITHUB_REPO
  5. git push origin master

Now you can work with it just like any other github repo. To pull in patches from upstream, simply run git pull upstream master && git push origin master.

Pass a data.frame column name to a function

Another way is to use tidy evaluation approach. It is pretty straightforward to pass columns of a data frame either as strings or bare column names. See more about tidyeval here.


df <- data.frame(B = rnorm(10), D = rnorm(10))

Use column names as strings

fun3 <- function(x, ...) {
  # capture strings and create variables
  dots <- ensyms(...)
  # unquote to evaluate inside dplyr verbs
  summarise_at(x, vars(!!!dots), list(~ max(., na.rm = TRUE)))

fun3(df, "B")
#>          B
#> 1 1.715065

fun3(df, "B", "D")
#>          B        D
#> 1 1.715065 1.786913

Use bare column names

fun4 <- function(x, ...) {
  # capture expressions and create quosures
  dots <- enquos(...)
  # unquote to evaluate inside dplyr verbs
  summarise_at(x, vars(!!!dots), list(~ max(., na.rm = TRUE)))

fun4(df, B)
#>          B
#> 1 1.715065

fun4(df, B, D)
#>          B        D
#> 1 1.715065 1.786913

Created on 2019-03-01 by the reprex package (v0.2.1.9000)

Select top 2 rows in Hive

Yes, here you can use LIMIT.

You can try it by the below query:

SELECT * FROM employee_list SORT BY salary DESC LIMIT 2

How can I convert String to Int?

You can convert string to an integer value with the help of parse method.


int val = Int32.parse(stringToBeParsed);
int x = Int32.parse(1234);

How to add Options Menu to Fragment in Android

Set setHasMenuOptions(true) works if application has a theme with Actionbar such as Theme.MaterialComponents.DayNight.DarkActionBar or Activity has it's own Toolbar, otherwise onCreateOptionsMenu in fragment does not get called.

If you want to use standalone Toolbar you either need to get activity and set your Toolbar as support action bar with

(requireActivity() as? MainActivity)?.setSupportActionBar(toolbar)

which lets your fragment onCreateOptionsMenu to be called.

Other alternative is, you can inflate your Toolbar's own menu with toolbar.inflateMenu( and item listener with

toolbar.setOnMenuItemClickListener {
   // do something

How to programmatically add controls to a form in VB.NET

You can get your Button1 location and than increase the Y value every time you click on it.

Public Class Form1
    Dim BtnCoordinate As Point
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim btn As Button = New Button
        BtnCoordinate.Y += Button1.Location.Y + 4
        With btn
            .Location = New Point(BtnCoordinate)
            .Text = TextBox1.Text
            .ForeColor = Color.Black
        End With
        Me.StartPosition = FormStartPosition.CenterScreen
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Button1Coordinate = Button1.Location
    End Sub
End Class

Heatmap in matplotlib with pcolor?

The python seaborn module is based on matplotlib, and produces a very nice heatmap.

Below is an implementation with seaborn, designed for the ipython/jupyter notebook.

import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
%matplotlib inline
# import the data directly into a pandas dataframe
nba = pd.read_csv("", index_col='Name  ')
# remove index title = ""
# normalize data columns
nba_norm = (nba - nba.mean()) / (nba.max() - nba.min())
# relabel columns
labels = ['Games', 'Minutes', 'Points', 'Field goals made', 'Field goal attempts', 'Field goal percentage', 'Free throws made', 
          'Free throws attempts', 'Free throws percentage','Three-pointers made', 'Three-point attempt', 'Three-point percentage', 
          'Offensive rebounds', 'Defensive rebounds', 'Total rebounds', 'Assists', 'Steals', 'Blocks', 'Turnover', 'Personal foul']
nba_norm.columns = labels
# set appropriate font and dpi
sns.set_style({"savefig.dpi": 100})
# plot it out
ax = sns.heatmap(nba_norm,, linewidths=.1)
# set the x-axis labels on the top
# rotate the x-axis labels
# get figure (usually obtained via "fig,ax=plt.subplots()" with matplotlib)
fig = ax.get_figure()
# specify dimensions and save
fig.set_size_inches(15, 20)

The output looks like this: seaborn nba heatmap I used the matplotlib Blues color map, but personally find the default colors quite beautiful. I used matplotlib to rotate the x-axis labels, as I couldn't find the seaborn syntax. As noted by grexor, it was necessary to specify the dimensions (fig.set_size_inches) by trial and error, which I found a bit frustrating.

As noted by Paul H, you can easily add the values to heat maps (annot=True), but in this case I didn't think it improved the figure. Several code snippets were taken from the excellent answer by joelotz.

ssh: Could not resolve hostname [hostname]: nodename nor servname provided, or not known

In my case I was trying ssh like this

ssh [email protected]:22 

when the correct format is:

ssh [email protected] -p 22 

How can I define an array of objects?


person: Array<{
  name: string;
  age: number;

Enable PHP Apache2

You have two ways to enable it.

First, you can set the absolute path of the php module file in your httpd.conf file like this:

LoadModule php5_module /path/to/mods-available/

Second, you can link the module file to the mods-enabled directory:

ln -s /path/to/mods-available/ /path/to/mods-enabled/

jQuery: Test if checkbox is NOT checked

Simple and easy to check or unchecked condition

<input type="checkbox" id="ev-click" name="" value="" >

    $( "#ev-click" ).click(function() {

Angular 2: Get Values of Multiple Checked Checkboxes

<input type="checkbox" name="options" value="option" (change)="updateChecked(option, $event)" /> 

export class MyComponent {
  checked: boolean[] = [];
  updateChecked(option, event) {
    this.checked[option]=event; // or `` not sure what this event looks like

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

try this=> numpy.array(r) or numpy.array(yourvariable) followed by the command to compare whatever you wish to.

How to update attributes without validation

USE update_attribute instead of update_attributes

Updates a single attribute and saves the record without going through the normal validation procedure.

if a.update_attribute('state', a.state)

Note:- 'update_attribute' update only one attribute at a time from the code given in question i think it will work for you. Read timed out under Tomcat

Server is trying to read data from the request, but its taking longer than the timeout value for the data to arrive from the client. Timeout here would typically be tomcat connector -> connectionTimeout attribute.


Client has a read timeout set, and server is taking longer than that to respond.

No. That would cause a timeout at the client.

One of the threads i went through, said this can happen with high concurrency and if the keepalive is enabled.

That is obviously guesswork, and completely incorrect. It happens if and only if no data arrives within the timeout. Period. Load and keepalive and concurrency have nothing to do with it whatsoever.

It just means the client isn't sending. You don't need to worry about it. Browser clients come and go in all sorts of strange ways.

Changing Fonts Size in Matlab Plots

Jonas's answer is good, but I had to modify it slightly to get every piece of text on the screen to change:



What represents a double in sql server?

A Float represents double in SQL server. You can find a proof from the coding in C# in visual studio. Here I have declared Overtime as a Float in SQL server and in C#. Thus I am able to convert

int diff=4;
attendance.OverTime = Convert.ToDouble(diff);

Here OverTime is declared float type

How to calculate the number of occurrence of a given character in each row of a column of strings?

s <- "aababacababaaathhhhhslsls jsjsjjsaa ghhaalll"
p <- "a"
s2 <- gsub(p,"",s)
numOcc <- nchar(s) - nchar(s2)

May not be the efficient one but solve my purpose.

no debugging symbols found when using gdb

You should also try -ggdb instead of -g if you're compiling for Android!

Python integer division yields float

Hope it might help someone instantly.

Behavior of Division Operator in Python 2.7 and Python 3

In Python 2.7: By default, division operator will return integer output.

to get the result in double multiple 1.0 to "dividend or divisor"

100/35 => 2 #(Expected is 2.857142857142857)
(100*1.0)/35 => 2.857142857142857
100/(35*1.0) => 2.857142857142857

In Python 3

// => used for integer output
/ => used for double output

100/35 => 2.857142857142857
100//35 => 2
100.//35 => 2.0    # floating-point result if divsor or dividend real

Replace new line/return with space using regex

The new line separator is different for different OS-es - '\r\n' for Windows and '\n' for Linux.

To be safe, you can use regex pattern \R - the linebreak matcher introduced with Java 8:

String inlinedText = text.replaceAll("\\R", " ");

how to get the child node in div using javascript

var tds = document.getElementById("ctl00_ContentPlaceHolder1_Jobs_dlItems_ctl01_a").getElementsByTagName("td");
time = tds[0].firstChild.value;
address = tds[3].firstChild.value;

How to find where javaw.exe is installed?

It worked to me:

    String javaHome = System.getProperty("java.home");
    File f = new File(javaHome);
    f = new File(f, "bin");
    f = new File(f, "javaw.exe"); //or f = new File(f, "javaws.exe"); //work too
    System.out.println(f + "    exists: " + f.exists());

How do I initialise all entries of a matrix with a specific value?

As mentioned in other answers you can use:

>> tic; x=5*ones(10,1); toc
Elapsed time is 0.000415 seconds.

An even faster method is:

>> tic;  x=5; x=x(ones(10,1)); toc
Elapsed time is 0.000257 seconds.

Loop through properties in JavaScript object with Lodash

Yes you can and lodash is not needed... i.e.

for (var key in myObject.options) {
  // check also if property is not inherited from prototype
  if (myObject.options.hasOwnProperty(key)) { 
    var value = myObject.options[key];

Edit: the accepted answer (_.forOwn()) should be

Redirecting to a relative URL in JavaScript

I'm trying to redirect my current web site to other section on the same page, using JavaScript. This follow code work for me:


What is a handle in C++?

A handle can be anything from an integer index to a pointer to a resource in kernel space. The idea is that they provide an abstraction of a resource, so you don't need to know much about the resource itself to use it.

For instance, the HWND in the Win32 API is a handle for a Window. By itself it's useless: you can't glean any information from it. But pass it to the right API functions, and you can perform a wealth of different tricks with it. Internally you can think of the HWND as just an index into the GUI's table of windows (which may not necessarily be how it's implemented, but it makes the magic make sense).

EDIT: Not 100% certain what specifically you were asking in your question. This is mainly talking about pure C/C++.

Linux c++ error: undefined reference to 'dlopen'

You have to link against libdl, add


to your linker options

Is it possible to use 'else' in a list comprehension?

Yes, else can be used in Python inside a list comprehension with a Conditional Expression ("ternary operator"):

>>> [("A" if b=="e" else "c") for b in "comprehension"]
['c', 'c', 'c', 'c', 'c', 'A', 'c', 'A', 'c', 'c', 'c', 'c', 'c']

Here, the parentheses "()" are just to emphasize the conditional expression, they are not necessarily required (Operator precedence).

Additionaly, several expressions can be nested, resulting in more elses and harder to read code:

>>> ["A" if b=="e" else "d" if True else "x" for b in "comprehension"]
['d', 'd', 'd', 'd', 'd', 'A', 'd', 'A', 'd', 'd', 'd', 'd', 'd']

On a related note, a comprehension can also contain its own if condition(s) at the end:

>>> ["A" if b=="e" else "c" for b in "comprehension" if False]
>>> ["A" if b=="e" else "c" for b in "comprehension" if "comprehension".index(b)%2]
['c', 'c', 'A', 'A', 'c', 'c']

Conditions? Yes, multiple ifs are possible, and actually multiple fors, too:

>>> [i for i in range(3) for _ in range(3)]
[0, 0, 0, 1, 1, 1, 2, 2, 2]
>>> [i for i in range(3) if i for _ in range(3) if _ if True if True]
[1, 1, 2, 2]

(The single underscore _ is a valid variable name (identifier) in Python, used here just to show it's not actually used. It has a special meaning in interactive mode)

Using this for an additional conditional expression is possible, but of no real use:

>>> [i for i in range(3)]
[0, 1, 2]
>>> [i for i in range(3) if i]
[1, 2]
>>> [i for i in range(3) if (True if i else False)]
[1, 2]

Comprehensions can also be nested to create "multi-dimensional" lists ("arrays"):

>>> [[i for j in range(i)] for i in range(3)]
[[], [1], [2, 2]]

Last but not least, a comprehension is not limited to creating a list, i.e. else and if can also be used the same way in a set comprehension:

>>> {i for i in "set comprehension"}
{'o', 'p', 'm', 'n', 'c', 'r', 'i', 't', 'h', 'e', 's', ' '}

and a dictionary comprehension:

>>> {k:v for k,v in [("key","value"), ("dict","comprehension")]}
{'key': 'value', 'dict': 'comprehension'}

The same syntax is also used for Generator Expressions:

>>> for g in ("a" if b else "c" for b in "generator"):
...     print(g, end="")

which can be used to create a tuple (there is no tuple comprehension).

Further reading:

Make the current commit the only (initial) commit in a Git repository?

For that use Shallow Clone command git clone --depth 1 URL - It will clones only the current HEAD of the repository

Is a DIV inside a TD a bad idea?

I have faced the problem by placing a <div> inside <td>.

I was unable to identify the div using document.getElementById() if i place that inside td. But outside, it was working fine.

Using SED with wildcard

So, the concept of a "wildcard" in Regular Expressions works a bit differently. In order to match "any character" you would use "." The "*" modifier means, match any number of times.

Return value of x = os.system(..)

os.system('command') returns a 16 bit number, which first 8 bits from left(lsb) talks about signal used by os to close the command, Next 8 bits talks about return code of command.

Refer my answer for more detail in What is the return value of os.system() in Python?

How to convert a DataTable to a string in C#?

    /// <summary>
    /// Dumps the passed DataSet obj for debugging as list of html tables
    /// </summary>
    /// <param name="msg"> the msg attached </param>
    /// <param name="ds"> the DataSet object passed for Dumping </param>
    /// <returns> the nice looking dump of the DataSet obj in html format</returns>
    public static string DumpHtmlDs(string msg, ref System.Data.DataSet ds)
        StringBuilder objStringBuilder = new StringBuilder();

        if (ds == null)
            objStringBuilder.AppendLine("Null dataset passed ");
            return objStringBuilder.ToString();

        objStringBuilder.AppendLine("<p>" + msg + " START </p>");
        if (ds != null)
            if (ds.Tables == null)
                objStringBuilder.AppendLine("ds.Tables == null ");
                return objStringBuilder.ToString();

            foreach (System.Data.DataTable dt in ds.Tables)

                if (dt == null)
                    objStringBuilder.AppendLine("ds.Tables == null ");

                //objStringBuilder.AppendLine("================= My TableName is  " +
                //dt.TableName + " ========================= START");
                int colNumberInRow = 0;
                objStringBuilder.Append("<tr><th>row number</th>");
                foreach (System.Data.DataColumn dc in dt.Columns)
                    if (dc == null)
                        objStringBuilder.AppendLine("DataColumn is null ");

                    objStringBuilder.Append(" <th> |" + colNumberInRow.ToString() + " | ");
                    objStringBuilder.Append(  dc.ColumnName.ToString() + " </th> ");
                } //eof foreach (DataColumn dc in dt.Columns)

                int rowNum = 0;
                foreach (System.Data.DataRow dr in dt.Rows)
                    objStringBuilder.Append("<tr><td> row - | " + rowNum.ToString() + " | </td>");
                    int colNumber = 0;
                    foreach (System.Data.DataColumn dc in dt.Columns)
                        objStringBuilder.Append(" <td> |" + colNumber + "|" );
                        objStringBuilder.Append(dr[dc].ToString() + "  </td>");
                    } //eof foreach (DataColumn dc in dt.Columns)
                    objStringBuilder.AppendLine(" </tr>");
                }   //eof foreach (DataRow dr in dt.Rows)

                objStringBuilder.AppendLine("<p>" + msg + " END </p>");
            }   //eof foreach (DataTable dt in ds.Tables)

        } //eof if ds !=null 

            objStringBuilder.AppendLine("NULL DataSet object passed for debugging !!!");
        return objStringBuilder.ToString();


Using strtok with a std::string

Duplicate the string, tokenize it, then free it.

char *dup = strdup(str.c_str());
token = strtok(dup, " ");

How to remove item from a python list in a loop?

The already-mentioned list comprehension approach is probably your best bet. But if you absolutely want to do it in-place (for example if x is really large), here's one way:

x = ["ok", "jj", "uy", "poooo", "fren"]
while index < len(x):
    if len(x[index]) != 2:
        print "length of %s is: %s" %(x[index], len(x[index]))
        del x[index]

How to extract the nth word and count word occurrences in a MySQL string?

The following is a proposed solution for the OP's specific problem (extracting the 2nd word of a string), but it should be noted that, as mc0e's answer states, actually extracting regex matches is not supported out-of-the-box in MySQL. If you really need this, then your choices are basically to 1) do it in post-processing on the client, or 2) install a MySQL extension to support it.

BenWells has it very almost correct. Working from his code, here's a slightly adjusted version:

  LOCATE(' ', sentence) + CHAR_LENGTH(' '),
  LOCATE(' ', sentence,
  ( LOCATE(' ', sentence) + 1 ) - ( LOCATE(' ', sentence) + CHAR_LENGTH(' ') )

As a working example, I used:

  LOCATE(' ', sentence) + CHAR_LENGTH(' '),
  LOCATE(' ', sentence,
  ( LOCATE(' ', sentence) + 1 ) - ( LOCATE(' ', sentence) + CHAR_LENGTH(' ') )
) as string
FROM (SELECT 'THIS IS A TEST' AS sentence) temp

This successfully extracts the word IS

how to access parent window object using jquery?

or you can use another approach:

$( "#serverMsg", window.opener.document )

How do I get the last character of a string?

public String lastChars(String a) {
String str1 =a.substring(b.length()-1);
return str1;

How to rotate the background image in the container?

Very easy method, you rotate one way, and the contents the other. Requires a square though

    background : url('someImage.jpg');
    transform: rotate(-30deg);
#element:hover >*{
    transform: rotate(30deg);

Is it possible to declare a public variable in vba and assign a default value?

Little-Known Fact:
A named range can refer to a value instead of specific cells.

This could be leveraged to act like a "global variable", plus you can refer to the value from VBA and in a worksheet cell, and the assigned value will even persist after closing & re-opening the workbook!

  • To "declare" the name myVariable and assign it a value of 123:

    ThisWorkbook.Names.Add "myVariable", 123
  • To retrieve the value (for example to display the value in a MsgBox):

      MsgBox [myVariable]
  • Alternatively, you could refer to the name with a string: (identical result as square brackets)

    MsgBox Evaluate("myVariable")
  • To use the value on a worksheet just use it's name in your formula as-is:

  • In fact, you could even store function expressions: (sort of like in JavaScript)
    (Admittedly, I can't actually think of a situation where this would be beneficial - but I don't use them in JS either.)

    ThisWorkbook.Names.Add "myDay", "=if(isodd(day(today())),""on day"",""off day"")"

Square brackets are just a shortcut for the Evaluate method. I've heard that using them is considered messy or "hacky", but I've had no issues and their use in Excel is supported by Microsoft.

There is probably also a way use the Range function to refer to these names, but I don't see any advantage so I didn't look very deeply into it.

More info:

Yarn: How to upgrade yarn version using terminal?

Since you already have yarn installed and only want to upgrade/update. you can simply use

yarn self-update

Find ref here

Remove spaces from std::string in C++

Removes all whitespace characters such as tabs and line breaks (C++11):

string str = " \n AB cd \t efg\v\n";
str = regex_replace(str,regex("\\s"),"");

If Else in LINQ

Answer above is not suitable for complicate Linq expression. All you need is:

// set up the "main query"
var test = from p in _db.test select _db.test;
// if str1 is not null, add a where-condition
if(str1 != null)
    test = test.Where(p => p.test == str);

Combine two columns and add into one new column

You don't need to store the column to reference it that way. Try this:

To set up:

  (zipcode text NOT NULL, city text NOT NULL, state text NOT NULL);
INSERT INTO tbl VALUES ('10954', 'Nanuet', 'NY');

We can see we have "the right stuff":

\pset border 2
| zipcode |  city  | state |
| 10954   | Nanuet | NY    |

Now add a function with the desired "column name" which takes the record type of the table as its only parameter:

CREATE FUNCTION combined(rec tbl)
  RETURNS text
AS $$
  SELECT $1.zipcode || ' - ' || $ || ', ' || $1.state;

This creates a function which can be used as if it were a column of the table, as long as the table name or alias is specified, like this:

SELECT *, tbl.combined FROM tbl;

Which displays like this:

| zipcode |  city  | state |      combined      |
| 10954   | Nanuet | NY    | 10954 - Nanuet, NY |

This works because PostgreSQL checks first for an actual column, but if one is not found, and the identifier is qualified with a relation name or alias, it looks for a function like the above, and runs it with the row as its argument, returning the result as if it were a column. You can even index on such a "generated column" if you want to do so.

Because you're not using extra space in each row for the duplicated data, or firing triggers on all inserts and updates, this can often be faster than the alternatives.

What is the difference between application server and web server?

An application server is typically designed and deployed to facilitate longer running processes that will also be more resource intensive.

A web server is used for short bursts that are not resource intensive, generally. This is mostly to facilitate serving up web based traffic.

live output from subprocess command

I think that the subprocess.communicate method is a bit misleading: it actually fills the stdout and stderr that you specify in the subprocess.Popen.

Yet, reading from the subprocess.PIPE that you can provide to the subprocess.Popen's stdout and stderr parameters will eventually fill up OS pipe buffers and deadlock your app (especially if you've multiple processes/threads that must use subprocess).

My proposed solution is to provide the stdout and stderr with files - and read the files' content instead of reading from the deadlocking PIPE. These files can be tempfile.NamedTemporaryFile() - which can also be accessed for reading while they're being written into by subprocess.communicate.

Below is a sample usage:

            with ProcessRunner(('python', ''), env=os.environ.copy(), seconds_to_wait=0.01) as process_runner:
                for out in process_runner:
        catch ProcessError as e:

And this is the source code which is ready to be used with as many comments as I could provide to explain what it does:

If you're using python 2, please make sure to first install the latest version of the subprocess32 package from pypi.

import os
import sys
import threading
import time
import tempfile
import logging

if == 'posix' and sys.version_info[0] < 3:
    # Support python 2
    import subprocess32 as subprocess
    # Get latest and greatest from python 3
    import subprocess

logger = logging.getLogger(__name__)

class ProcessError(Exception):
    """Base exception for errors related to running the process"""

class ProcessTimeout(ProcessError):
    """Error that will be raised when the process execution will exceed a timeout"""

class ProcessRunner(object):
    def __init__(self, args, env=None, timeout=None, bufsize=-1, seconds_to_wait=0.25, **kwargs):
        Constructor facade to subprocess.Popen that receives parameters which are more specifically required for the
        Process Runner. This is a class that should be used as a context manager - and that provides an iterator
        for reading captured output from subprocess.communicate in near realtime.

        Example usage:

            with ProcessRunner(('python', task_file_path), env=os.environ.copy(), seconds_to_wait=0.01) as process_runner:
                for out in process_runner:
        catch ProcessError as e:

        :param args: same as subprocess.Popen
        :param env: same as subprocess.Popen
        :param timeout: same as subprocess.communicate
        :param bufsize: same as subprocess.Popen
        :param seconds_to_wait: time to wait between each readline from the temporary file
        :param kwargs: same as subprocess.Popen
        self._seconds_to_wait = seconds_to_wait
        self._process_has_timed_out = False
        self._timeout = timeout
        self._process_done = False
        self._std_file_handle = tempfile.NamedTemporaryFile()
        self._process = subprocess.Popen(args, env=env, bufsize=bufsize,
                                         stdout=self._std_file_handle, stderr=self._std_file_handle, **kwargs)
        self._thread = threading.Thread(target=self._run_process)
        self._thread.daemon = True

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):

    def __iter__(self):
        # read all output from stdout file that subprocess.communicate fills
        with open(, 'r') as stdout:
            # while process is alive, keep reading data
            while not self._process_done:
                out = stdout.readline()
                out_without_trailing_whitespaces = out.rstrip()
                if out_without_trailing_whitespaces:
                    # yield stdout data without trailing \n
                    yield out_without_trailing_whitespaces
                    # if there is nothing to read, then please wait a tiny little bit

            # this is a hack: terraform seems to write to buffer after process has finished
            out =
            if out:
                yield out

        if self._process_has_timed_out:
            raise ProcessTimeout('Process has timed out')

        if self._process.returncode != 0:
            raise ProcessError('Process has failed')

    def _run_process(self):
            # Start gathering information (stdout and stderr) from the opened process
            # Graceful termination of the opened process
        except subprocess.TimeoutExpired:
            self._process_has_timed_out = True
            # Force termination of the opened process

        self._process_done = True

    def return_code(self):
        return self._process.returncode

SQL server 2008 backup error - Operating system error 5(failed to retrieve text for this error. Reason: 15105)

It looks like the SQL Server doesn't have permission to access file C:\backup.bak. I would check the permissions of the account that is assigned to the SQL Server service account.

As part of the solution, you may want to save your backup files to somewhere other that the root of the C: drive. That might be one reason why you are having permission problems.

What is the significance of url-pattern in web.xml and how to configure servlet?

Servlet-mapping has two child tags, url-pattern and servlet-name. url-pattern specifies the type of urls for which, the servlet given in servlet-name should be called. Be aware that, the container will use case-sensitive for string comparisons for servlet matching.

First specification of url-pattern a web.xml file for the server context on the servlet container at server .com matches the pattern in <url-pattern>/status/*</url-pattern> as follows:               = Matches    = Matches                        = Matches                = Does not match

Second specification of url-pattern A context located at the path /examples on the Agent at matches the pattern in <url-pattern>*.map</url-pattern> as follows:    = Matches     = Matches          = Matches    = Does not match, the extension is uppercase  =Does not match, the extension is mapi rather than map`

Third specification of url-mapping,A mapping that contains the pattern <url-pattern>/</url-pattern> matches a request if no other pattern matches. This is the default mapping. The servlet mapped to this pattern is called the default servlet.

The default mapping is often directed to the first page of an application. Explicitly providing a default mapping also ensures that malformed URL requests into the application return are handled by the application rather than returning an error.

The servlet-mapping element below maps the server servlet instance to the default mapping.


For the context that contains this element, any request that is not handled by another mapping is forwarded to the server servlet.

And Most importantly we should Know about Rule for URL path mapping

  1. The container will try to find an exact match of the path of the request to the path of the servlet. A successful match selects the servlet.
  2. The container will recursively try to match the longest path-prefix. This is done by stepping down the path tree a directory at a time, using the ’/’ character as a path separator. The longest match determines the servlet selected.
  3. If the last segment in the URL path contains an extension (e.g. .jsp), the servlet container will try to match a servlet that handles requests for the extension. An extension is defined as the part of the last segment after the last ’.’ character.
  4. If neither of the previous three rules result in a servlet match, the container will attempt to serve content appropriate for the resource requested. If a “default” servlet is defined for the application, it will be used.

Reference URL Pattern

Creating a directory in /sdcard fails

There are Many Things You Need to worry about 1.If you are using Android Bellow Marshmallow then you have to set permesions in Manifest File. 2. If you are using later Version of Android means from Marshmallow to Oreo now Either you have to go to the App Info and Set there manually App permission for Storage. if you want to Set it at Run Time you can do that by below code

public  boolean isStoragePermissionGranted() {
if (Build.VERSION.SDK_INT >= 23) {
    if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
            == PackageManager.PERMISSION_GRANTED) {
        Log.v(TAG,"Permission is granted");
        return true;
    } else {

        Log.v(TAG,"Permission is revoked");
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
        return false;
else { //permission is automatically granted on sdk<23 upon installation
    Log.v(TAG,"Permission is granted");
    return true;


Hibernate: failed to lazily initialize a collection of role, no session or session was closed

I was experiencing the same issue so just added the @Transactional annotation from where I was calling the DAO method. It just works. I think the problem was Hibernate doesn't allow to retrieve sub-objects from the database unless specifically all the required objects at the time of calling.

Centering image and text in R Markdown for a PDF report

none of the answers worked but this


but then the following problem is that it works for only one figure and then will not for any other figures.

I just started learning R I knew it was going to be difficult but what's worst is that there is little to no info that I can refer to.

APT command line interface-like yes/no input?

One-liner with Python 3.8 and above:

while res:= input("When correct, press enter to continue...").lower() not in {'y','yes','Y','YES',''}: pass

What underlies this JavaScript idiom: var self = this?

See this article on (Ed: The article has been updated since originally linked)

self is being used to maintain a reference to the original this even as the context is changing. It's a technique often used in event handlers (especially in closures).

Edit: Note that using self is now discouraged as window.self exists and has the potential to cause errors if you are not careful.

What you call the variable doesn't particularly matter. var that = this; is fine, but there's nothing magic about the name.

Functions declared inside a context (e.g. callbacks, closures) will have access to the variables/function declared in the same scope or above.

For example, a simple event callback:

function MyConstructor(options) {_x000D_
  let that = this;_x000D_
  this.someprop = options.someprop || 'defaultprop';_x000D_
  document.addEventListener('click', (event) => {_x000D_
new MyConstructor({_x000D_
  someprop: "Hello World"_x000D_

Does a TCP socket connection have a "keep alive"?

TCP sockets remain open till they are closed.

That said, it's very difficult to detect a broken connection (broken, as in a router died, etc, as opposed to closed) without actually sending data, so most applications do some sort of ping/pong reaction every so often just to make sure the connection is still actually alive.

What does body-parser do with express?

Yes we can work without body-parser. When you don't use that you get the raw request, and your body and headers are not in the root object of request parameter . You will have to individually manipulate all the fields.

Or you can use body-parser, as the express team is maintaining it .

What body-parser can do for you: It simplifies the request.
How to use it: Here is example:

Install npm install body-parser --save

This how to use body-parser in express:

const express = require('express'),
      app = express(),
      bodyParser = require('body-parser');

// support parsing of application/json type post data

//support parsing of application/x-www-form-urlencoded post data
app.use(bodyParser.urlencoded({ extended: true }));


And then you can get body and headers in root request object . Example"/posturl",function(req,res,next){

Select parent element of known element in Selenium

Let's consider your DOM as

    <!-- some other icons and texts -->

Now that you need to select parent tag 'a' based on <span> text, then use


Explanation: Select the node based on its child node's value

Remove specific characters from a string in Python

>>> line = "abc#@!?efg12;:?"
>>> ''.join( c for c in line if  c not in '?:!/;' )

java.sql.SQLException: - ORA-01000: maximum open cursors exceeded

I faced the same issue because I was querying db for more than 1000 iterations. I have used try and finally in my code. But was still getting error.

To solve this I just logged into oracle db and ran below query:

ALTER SYSTEM SET open_cursors = 8000 SCOPE=BOTH;

And this solved my problem immediately.

How can I perform a str_replace in JavaScript, replacing text in JavaScript?

There are already multiple answers using str.replace() (which is fair enough for this question) and regex but you can use combination of str.split() and join() together which is faster than str.replace() and regex.

Below is working example:

var text = "this is some sample text that i want to replace";_x000D_
console.log(text.split("want").join("dont want"));

How to get a table creation script in MySQL Workbench?

  1. Open MySQL Workbench (6.3 CE)
  2. In "Navigator" select "Management"
  3. Then select "Data Export" (Here select the table whose create script you wish to export)
  4. In Drop down select "Dump Structure and Data"
  5. Select checkbox "Include Create Schema"
  6. Click the button "Start Export" Once export is complete it will display the location in which exported file is dumped in your system. Go to the location and open the exported file to find table creation script.

Or Check

jquery count li elements inside ul -> length?

If you have a dom object of the ul, use the following.


A simple example

window.setInterval(function() {_x000D_
  let ul = $('#ul');                 // Get the ul_x000D_
  let length = ul.children().length; // Count of the child nodes._x000D_
  // The show!_x000D_
  ul.append('<li>Item ' + (length + 1) + '</li>');_x000D_
  if (5 <= length) {_x000D_
    length = -1;_x000D_
  $('#ul_length').text(length + 1);_x000D_
}, 1000);
<script src=""></script>_x000D_
<h4>Count of the child nodes: <span id='ul_length'>0</span></h4>_x000D_
<ul id="ul"></ul>

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.

Error parsing XHTML: The content of elements must consist of well-formed character data or markup

I solved this converting the JSP from XHTML to HTML, doing this in the begining:

<%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">


Is there a better way to run a command N times in bash?

All of the existing answers appear to require bash, and don't work with a standard BSD UNIX /bin/sh (e.g., ksh on OpenBSD).

The below code should work on any BSD:

$ echo {1..4}
$ seq 4
sh: seq: not found
$ for i in $(jot 4); do echo e$i; done

How to replace a set of tokens in a Java String?

I used

String template = "Hello %s Please find attached %s which is due on %s";

String message = String.format(template, name, invoiceNumber, dueDate);

Is it better to return null or empty collection?

Empty is much more consumer friendly.

There is a clear method of making up an empty enumerable:


JavaScript post request like a form submit

Rakesh Pai's answer is amazing, but there is an issue that occurs for me (in Safari) when I try to post a form with a field called submit. For example, post_to_url("",{ submit: "submit" } );. I have patched the function slightly to walk around this variable space collision.

    function post_to_url(path, params, method) {
        method = method || "post";

        var form = document.createElement("form");

        //Move the submit function to another variable
        //so that it doesn't get overwritten.
        form._submit_function_ = form.submit;

        form.setAttribute("method", method);
        form.setAttribute("action", path);

        for(var key in params) {
            var hiddenField = document.createElement("input");
            hiddenField.setAttribute("type", "hidden");
            hiddenField.setAttribute("name", key);
            hiddenField.setAttribute("value", params[key]);


        form._submit_function_(); //Call the renamed function.
    post_to_url("", { submit: "submit" } ); //Works!

Most common C# bitwise operations on enums

For the best performance and zero garbage, use this:

using System;
using T = MyNamespace.MyFlags;

namespace MyNamespace
    public enum MyFlags
        None = 0,
        Flag1 = 1,
        Flag2 = 2

    static class MyFlagsEx
        public static bool Has(this T type, T value)
            return (type & value) == value;

        public static bool Is(this T type, T value)
            return type == value;

        public static T Add(this T type, T value)
            return type | value;

        public static T Remove(this T type, T value)
            return type & ~value;

The following untracked working tree files would be overwritten by merge, but I don't care

One way to do this is by stashing you local changes and pulling from the remote repo. In this way, you will not lose your local files as the files will go to the stash.

git add -A
git stash
git pull

You can check your local stashed files using this command - git stash list

What is the purpose of XSD files?

The xsd file is the schema of the xml file - it defines which elements may occur and their restrictions (like amount, order, boundaries, relationships,...)

Nested select statement in SQL Server

The answer provided by Joe Stefanelli is already correct.

SELECT name FROM (SELECT name FROM agentinformation) as a  

We need to make an alias of the subquery because a query needs a table object which we will get from making an alias for the subquery. Conceptually, the subquery results are substituted into the outer query. As we need a table object in the outer query, we need to make an alias of the inner query.

Statements that include a subquery usually take one of these forms:

  • WHERE expression [NOT] IN (subquery)
  • WHERE expression comparison_operator [ANY | ALL] (subquery)
  • WHERE [NOT] EXISTS (subquery)

Check for more subquery rules and subquery types.

More examples of Nested Subqueries.

  1. IN / NOT IN – This operator takes the output of the inner query after the inner query gets executed which can be zero or more values and sends it to the outer query. The outer query then fetches all the matching [IN operator] or non matching [NOT IN operator] rows.

  2. ANY – [>ANY or ANY operator takes the list of values produced by the inner query and fetches all the values which are greater than the minimum value of the list. The

e.g. >ANY(100,200,300), the ANY operator will fetch all the values greater than 100.

  1. ALL – [>ALL or ALL operator takes the list of values produced by the inner query and fetches all the values which are greater than the maximum of the list. The

e.g. >ALL(100,200,300), the ALL operator will fetch all the values greater than 300.

  1. EXISTS – The EXISTS keyword produces a Boolean value [TRUE/FALSE]. This EXISTS checks the existence of the rows returned by the sub query.

How to disable keypad popup when on edittext?

Just need to add property android:focusable="false" in particular EditText in the layout xml. Then you can write click listner for EditText without keypad popup.

How do you stylize a font in Swift?

Add Custom Font in Swift

  1. Drag and drop your font in your project.
  2. Double check that it is added in Copy Bundle Resource. (Build Phase -> Copy Bundle Resource).
  3. In your plist file add "Font Provided by application" and add your fonts with full name.
  4. Now use your font like: myLabel.font = UIFont (name: "GILLSANSCE-ROMAN", size: 20)

Excel- compare two cell from different sheet, if true copy value from other cell

In your destination field you want to use VLOOKUP like so:


VLOOKUP Arguments:

  1. The set fields you want to lookup.
  2. The table range you want to lookup up your value against. The first column of your defined table should be the column you want compared against your lookup field. The table range should also contain the value you want to display (Column F).
  3. This defines what field you want to display upon a match.
  4. FALSE tells VLOOKUP to do an exact match.

calculating execution time in c++

I have used the technique said above, still I found that the time given in the Code:Blocks IDE was more or less similar to the result obtained-(may be it will differ by little micro seconds)..

What's better at freeing memory with PHP: unset() or $var = null

$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    $a = 'a';
    $a = NULL;
$elapsed = microtime(true) - $start;

echo "took $elapsed seconds\r\n";

$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    $a = 'a';
$elapsed = microtime(true) - $start;

echo "took $elapsed seconds\r\n";

Per that it seems like "= null" is faster.

PHP 5.4 results:

  • took 0.88389301300049 seconds
  • took 2.1757180690765 seconds

PHP 5.3 results:

  • took 1.7235369682312 seconds
  • took 2.9490959644318 seconds

PHP 5.2 results:

  • took 3.0069220066071 seconds
  • took 4.7002630233765 seconds

PHP 5.1 results:

  • took 2.6272349357605 seconds
  • took 5.0403649806976 seconds

Things start to look different with PHP 5.0 and 4.4.


  • took 10.038941144943 seconds
  • took 7.0874409675598 seconds


  • took 7.5352551937103 seconds
  • took 6.6245851516724 seconds

Keep in mind microtime(true) doesn't work in PHP 4.4 so I had to use the microtime_float example given in / Example #1.

Convert string to buffer Node

You can use Buffer.from() to convert a string to buffer. More information on this can be found here

var buf = Buffer.from('some string', 'encoding');

for example

var buf = Buffer.from(bStr, 'utf-8');

How to get all Errors from ASP.Net MVC modelState?

var x = new Dictionary<string,string>();
for (var b = 0; b < ViewData.ModelState.Values.Count(); b++)
    if (ViewData.ModelState.Values.ElementAt(b).Errors.Count() > 0)
        x.Add(ViewData.ModelState.Keys.ElementAt(b), String.Join(",", ViewData
            .ModelState.Values.ElementAt(b).Errors.Select(c => c.ErrorMessage)));

Auto select file in Solution Explorer from its open tab

This isn't exactly what you're looking for, but it would automatically select the "active" file in the Solution Explorer:

Tools-->Options-->Projects and Solutions-->Track Active Item in Solution Explorer.

How can I run a php without a web server?

You can use these kind of programs to emulate an apache web server and run PHP on your computer:

Apache - MySQL Service detected with wrong path. / Ports already in use

about this specific issue:

12:35:23  [mysql]   Found Path: "C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqld" --defaults-file="C:\Program Files\MySQL\MySQL Server 5.5\my.ini" MySQL
12:35:23  [mysql]   Expected Path: c:\xampp\mysql\bin\mysqld.exe --defaults-file=c:\xampp\mysql\bin\my.ini mysql

notice that .exe is missing from 1st row at the end of mysqld.

To fix this, start regedit.exe and change HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\mysql ImagePath by adding the .exe extension.

Restart xampp control panel and this error should not show up.

TypeError: worker() takes 0 positional arguments but 1 was given

When doing Flask Basic auth I got this error and then I realized I had wrapped_view(**kwargs) and it worked after changing it to wrapped_view(*args, **kwargs).

How to resolve git status "Unmerged paths:"?

Another way of dealing with this situation if your files ARE already checked in, and your files have been merged (but not committed, so the merge conflicts are inserted into the file) is to run:

git reset

This will switch to HEAD, and tell git to forget any merge conflicts, and leave the working directory as is. Then you can edit the files in question (search for the "Updated upstream" notices). Once you've dealt with the conflicts, you can run

git add -p

which will allow you to interactively select which changes you want to add to the index. Once the index looks good (git diff --cached), you can commit, and then

git reset --hard

to destroy all the unwanted changes in your working directory.

Eclipse error: "Editor does not contain a main type"

private int user_movie_matrix[][];Th. should be `private int user_movie_matrix[][];.

private int user_movie_matrix[][]; should be private static int user_movie_matrix[][];

cfiltering(numberOfUsers, numberOfMovies); should be new cfiltering(numberOfUsers, numberOfMovies);

Whether or not the code works as intended after these changes is beyond the scope of this answer; there were several syntax/scoping errors.

How to determine the number of days in a month in SQL Server?

Most elegant solution: works for any @DATE


Throw it in a function or just use it inline. This answers the original question without all the extra junk in the other answers.

examples for dates from other answers:

SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'1/31/2009'),0))) Returns 31

SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'2404-feb-15'),0))) Returns 29

SELECT DAY(DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,-1,'2011-12-22'),0))) Returns 31

Select first empty cell in column F starting from row 1. (without using offset )

Public Sub SelectFirstBlankCell()
    Dim sourceCol As Integer, rowCount As Integer, currentRow As Integer
    Dim currentRowValue As String

    sourceCol = 6   'column F has a value of 6
    rowCount = Cells(Rows.Count, sourceCol).End(xlUp).Row

    'for every row, find the first blank cell and select it
    For currentRow = 1 To rowCount
        currentRowValue = Cells(currentRow, sourceCol).Value
        If IsEmpty(currentRowValue) Or currentRowValue = "" Then
            Cells(currentRow, sourceCol).Select
        End If
End Sub

If any column contains more than one empty cell continuously then this code will not work properly

iPad WebApp Full Screen in Safari

This only works after you save a bookmark to the app to the home screen. Not if you just browse to the site normally.

What is the difference between JAX-RS and JAX-WS?

Can JAX-RS do Asynchronous Request like JAX-WS?

1) I don't know if the JAX-RS API includes a specific mechanism for asynchronous requests, but this answer could still change based on the client implementation you use.

Can JAX-RS access a web service that is not running on the Java platform, and vice versa?

2) I can't think of any reason it wouldn't be able to.

What does it mean by "REST is particularly useful for limited-profile devices, such as PDAs and mobile phones"?

3) REST based architectures typically will use a lightweight data format, like JSON, to send data back and forth. This is in contrast to JAX-WS which uses XML. I don't see XML by itself so significantly heavier than JSON (which some people may argue), but with JAX-WS it's how much XML is used that ends up making REST with JSON the lighter option.

What does it mean by "JAX-RS do not require XML messages or WSDL service–API definitions?

4) As stated in 3, REST architectures often use JSON to send and receive data. JAX-WS uses XML. It's not that JSON is so significantly smaller than XML by itself. It's mostly that JAX-WS specification includes lots overhead in how it communicates.

On the point about WSDL and API definitions, REST will more frequently use the URI structure and HTTP commands to define the API rather than message types, as is done in the JAX-WS. This means that you don't need to publish a WSDL document so that other users of your service can know how to talk to your service. With REST you will still need to provide some documentation to other users about how the REST service is organized and what data and HTTP commands need to be sent.

How to drop all tables from a database with one SQL query?

As a follow-up to Dave.Gugg's answer, this would be the code someone would need to get all the DROP TABLE lines in MySQL:

WHERE TABLE_SCHEMA = 'your_database_name'

Decrementing for loops

for i in range(10,0,-1):
    print i,

The range() function will include the first value and exclude the second.

return results from a function (javascript, nodejs)

You are trying to execute an asynchronous function in a synchronous way, which is unfortunately not possible in Javascript.

As you guessed correctly, the roomId=results.... is executed when the loading from the DB completes, which is done asynchronously, so AFTER the resto of your code is completed.

Look at this article, it talks about .insert and not .find, but the idea is the same :

How to downgrade python from 3.7 to 3.6

Download and install Python 3.6 and then change the system path environment variable to that of python 3.6 and delete the python 3.7 path system environment variable. Restart pc for results.

Get cart item name, quantity all details woocommerce

This will show only Cart Items Count.

 global $woocommerce; 
    echo $woocommerce->cart->cart_contents_count;

Android - java.lang.SecurityException: Permission Denial: starting Intent

Select your proper configuration for launching Application.

In my case i found mistake as below image:

enter image description here

I had just changed like:

enter image description here

May it will help to someone, Thanks :)

How can I tell jaxb / Maven to generate multiple schema packages?

This can also be achieved by specifying stale file name for schemas and not clearing output directory. The default out put directory is automatically included in classpath which is little convenient. If we specify different output directory one has to take care of classpath to use this code in IDE. For example -


Source:Generating Code with JAXB Plugin

HTML5 textarea placeholder not appearing

Well, technically it does not have to be on the same line as long as there is no character between the ending ">" from start tag and the starting "<" from the closing tag. That is you need to end with ...></textarea> as in the example below:

       <textarea id = "comments" rows = "4" cols = "36" 
            placeholder = "Enter comments here"
            class = "valid"></textarea>

Unable to install boto3

try this way:

python -m pip install --user boto3

Understanding dispatch_async

The main reason you use the default queue over the main queue is to run tasks in the background.

For instance, if I am downloading a file from the internet and I want to update the user on the progress of the download, I will run the download in the priority default queue and update the UI in the main queue asynchronously.

dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
    //Background Thread
    dispatch_async(dispatch_get_main_queue(), ^(void){
        //Run UI Updates

MD5 is 128 bits but why is it 32 characters?

MD5 yields hexadecimal digits (0-15 / 0-F), so they are four bits each. 128 / 4 = 32 characters.

SHA-1 yields hexadecimal digits too (0-15 / 0-F), so 160 / 4 = 40 characters.

(Since they're mathematical operations, most hashing functions' output is commonly represented as hex digits.)

You were probably thinking of ASCII text characters, which are 8 bits.

Write / add data in JSON file using Node.js

Please try the following program. You might be expecting this output.

var fs = require('fs');

var data = {}
data.table = []
for (i=0; i <26 ; i++){
   var obj = {
       id: i,
       square: i * i
fs.writeFile ("input.json", JSON.stringify(data), function(err) {
    if (err) throw err;

Save this program in a javascript file, say, square.js.

Then run the program from command prompt using the command node square.js

What it does is, simply overwriting the existing file with new set of data, every time you execute the command.

Happy Coding.

How to prevent caching of my Javascript file?

You can append a queryString to your src and change it only when you will release an updated version:

<script src="test.js?v=1"></script>

In this way the browser will use the cached version until a new version will be specified (v=2, v=3...)

Fatal error: Class 'Illuminate\Foundation\Application' not found

In my situation, I didn't have the full vendor dependencies in place (composer file was messed up during original install) - so running any artisan commands caused a failure.

I was able to use the --no-scripts flag to prevent artisan from executing before it was included. Once my dependencies were in place, everything worked as expected.

composer update --no-scripts

XmlWriter to Write to a String Instead of to a File

You need to create a StringWriter, and pass that to the XmlWriter.

The string overload of the XmlWriter.Create is for a filename.


using (var sw = new StringWriter()) {
  using (var xw = XmlWriter.Create(sw)) {
    // Build Xml with xw.

  return sw.ToString();

Link to add to Google calendar

I've also been successful with this URL structure:

Base URL:

And let's say this is my event details:

Title: Event Title
Description: Example of some description. See more at
Location: 123 Some Place
Date: February 22, 2020
Start Time: 10:00am
End Time: 11:30am
Timezone: America/New York (GMT -5)

I'd convert my details into these parameters (URL encoded):


Example link:

Please note that since I've specified a timezone with the "ctz" parameter, I used the local times for the start and end dates. Alternatively, you can use UTC dates and exclude the timezone parameter, like this:


Example link:

How to fire AJAX request Periodically?

Yes, you could use either the JavaScript setTimeout() method or setInterval() method to invoke the code that you would like to run. Here's how you might do it with setTimeout:

function executeQuery() {
    url: 'url/path/here',
    success: function(data) {
      // do something with the return value here if you like
  setTimeout(executeQuery, 5000); // you could choose not to continue on failure...

$(document).ready(function() {
  // run the first time; all subsequent calls will take care of themselves
  setTimeout(executeQuery, 5000);

How to display both icon and title of action inside ActionBar?

You can add button in toolbar




create file btn_selector.xml in drawable

<?xml version="1.0" encoding="utf-8" ?>

<selector xmlns:android="">



private boolean isSelect = false;

OnClickListener for button:

private void myClick() {
    if (!isSelect) {
       //**your code**//
        isSelect = true;
    } else {//**your code**//
        isSelect = false;

JavaScript/jQuery: replace part of string?

You need to set the text after the replace call:

$('.element span').each(function() {_x000D_
  var text = $(this).text().replace('N/A, ', '');_x000D_
<script src=""></script>_x000D_
<div class="element">_x000D_
  <span>N/A, Category</span>_x000D_

Here's another cool way you can do it (hat tip @Felix King):

$(".element span").text(function(index, text) {
    return text.replace("N/A, ", "");

Navigate to another page with a button in angular 2

You can use routerLink in the following manner,

<input type="button" value="Add Bulk Enquiry" [routerLink]="['../addBulkEnquiry']" class="btn">

or use <button [routerLink]="['./url']"> in your case, for more info you could read the entire stacktrace on github

the other methods are also correct but they create a dependency on the component file.

Hope your concern is resolved.

How to start new activity on button click

From the sending Activity try the following code

   //EXTRA_MESSAGE is our key and it's value is 'packagename.MESSAGE'
    public static final String EXTRA_MESSAGE = "packageName.MESSAGE";

    protected void onCreate(Bundle savedInstanceState) {

        //Here we declare our send button
        Button sendButton = (Button) findViewById(;
        sendButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                //declare our intent object which takes two parameters, the context and the new activity name

                // the name of the receiving activity is declared in the Intent Constructor
                Intent intent = new Intent(getApplicationContext(), NameOfReceivingActivity.class);

                String sendMessage = "hello world"
                //put the text inside the intent and send it to another Activity
                intent.putExtra(EXTRA_MESSAGE, sendMessage);
                //start the activity


From the receiving Activity try the following code:

   protected void onCreate(Bundle savedInstanceState) {
 //use the getIntent()method to receive the data from another activity
 Intent intent = getIntent();

//extract the string, with the getStringExtra method
String message = intent.getStringExtra(NewActivityName.EXTRA_MESSAGE);

Then just add the following code to the AndroidManifest.xml file

  android:label="Title of the Activity"

How to parse string into date?

CONVERT(DateTime, ExpireDate, 121) AS ExpireDate

will do what is needed, result:

2012-04-24 00:00:00.000

Replace or delete certain characters from filenames of all files in a folder

The PowerShell answers are good, but the Rename-Item command doesn't work in the same target directory unless ALL of your files have the unwanted character in them (fails if it finds duplicates).

If you're like me and had a mix of good names and bad names, try this script instead (will replace spaces with an underscore):

Get-ChildItem -recurse -name | ForEach-Object { Move-Item $_ $_.replace(" ", "_") }

Entity framework code-first null foreign key

I prefer this (below):

public class User
    public int Id { get; set; }
    public int? CountryId { get; set; }
    public virtual Country Country { get; set; }

Because EF was creating 2 foreign keys in the database table: CountryId, and CountryId1, but the code above fixed that.

Elegant way to check for missing packages and install them?

The coming version of RStudio (1.2), already available as a preview, will include a feature to detect missing packages in library() and require() calls, and prompt the user to install them:

Detect missing R packages

Many R scripts open with calls to library() and require() to load the packages they need in order to execute. If you open an R script that references packages that you don’t have installed, RStudio will now offer to install all the needed packages in a single click. No more typing install.packages() repeatedly until the errors go away!

This seems to address the original concern of OP particularly well:

Many of them are novice/intermediate R users and don't realize that they have to install packages they don't already have.

Using DISTINCT and COUNT together in a MySQL Query


SELECT COUNT(DISTINCT productId) from  table_name WHERE keyword='$keyword'

fatal: This operation must be run in a work tree

You repository is bare, i.e. it does not have a working tree attached to it. You can clone it locally to create a working tree for it, or you could use one of several other options to tell Git where the working tree is, e.g. the --work-tree option for single commands, or the GIT_WORK_TREE environment variable. There is also the core.worktree configuration option but it will not work in a bare repository (check the man page for what it does).

# git --work-tree=/path/to/work/tree checkout master
# GIT_WORK_TREE=/path/to/work/tree git status

Assert that a method was called in a Python unit test

Yes, I can give you the outline but my Python is a bit rusty and I'm too busy to explain in detail.

Basically, you need to put a proxy in the method that will call the original, eg:

 class fred(object):
   def blog(self):
     print "We Blog"

 class methCallLogger(object):
   def __init__(self, meth):
     self.meth = meth

   def __call__(self, code=None):
     # would also log the fact that it invoked the method

 f = fred() = methCallLogger(

This StackOverflow answer about callable may help you understand the above.

In more detail:

Although the answer was accepted, due to the interesting discussion with Glenn and having a few minutes free, I wanted to enlarge on my answer:

# helper class defined elsewhere
class methCallLogger(object):
   def __init__(self, meth):
     self.meth = meth
     self.was_called = False

   def __call__(self, code=None):
     self.was_called = True

class fred(object):
   def blog(self):
     print "We Blog"

f = fred()
g = fred() = methCallLogger( = methCallLogger(

How can I save multiple documents concurrently in Mongoose/Node.js?

This is an old question, but it came up first for me in google results when searching "mongoose insert array of documents".

There are two options model.create() [mongoose] and model.collection.insert() [mongodb] which you can use. View a more thorough discussion here of the pros/cons of each option:

Mongoose (mongodb) batch insert?

Percentage width in a RelativeLayout

Since PercentRelativeLayout was deprecated in 26.0.0 and nested layouts like LinearLayout inside RelativeLayout have a negative impact on performance (Understanding the performance benefits of ConstraintLayout) the best option for you to achieve percentage width is to replace your RelativeLayout with ConstraintLayout.

This can be solved in two ways.

SOLUTION #1 Using guidelines with percentage offset

Layout Editor


        app:layout_constraintLeft_toLeftOf="@+id/host_input" />

        app:layout_constraintLeft_toLeftOf="@+id/port_input" />

        app:layout_constraintRight_toLeftOf="@+id/guideline" />

        app:layout_constraintRight_toRightOf="parent" />

        app:layout_constraintGuide_percent="0.8" />


SOLUTION #2 Using chain with weighted width for EditText

Layout Editor


        app:layout_constraintLeft_toLeftOf="@+id/host_input" />

        app:layout_constraintLeft_toLeftOf="@+id/port_input" />

        app:layout_constraintRight_toLeftOf="@+id/port_input" />

        app:layout_constraintRight_toRightOf="parent" />


In both cases, you get something like this

Result View

Sorting Directory.GetFiles()

Here's the VB.Net solution that I've used.

First make a class to compare dates:

Private Class DateComparer
    Implements System.Collections.IComparer

    Public Function Compare(ByVal info1 As Object, ByVal info2 As Object) As Integer Implements System.Collections.IComparer.Compare
        Dim FileInfo1 As System.IO.FileInfo = DirectCast(info1, System.IO.FileInfo)
        Dim FileInfo2 As System.IO.FileInfo = DirectCast(info2, System.IO.FileInfo)

        Dim Date1 As DateTime = FileInfo1.CreationTime
        Dim Date2 As DateTime = FileInfo2.CreationTime

        If Date1 > Date2 Then Return 1
        If Date1 < Date2 Then Return -1
        Return 0
    End Function
End Class

Then use the comparer while sorting the array:

Dim DirectoryInfo As New System.IO.DirectoryInfo("C:\")
Dim Files() As System.IO.FileInfo = DirectoryInfo.GetFiles()
Dim comparer As IComparer = New DateComparer()
Array.Sort(Files, comparer)

MySQL - Operand should contain 1 column(s)

This error can also occur if you accidentally use commas instead of AND in the ON clause of a JOIN:

JOIN joined_table ON (joined_table.column = table.column, joined_table.column2 = table.column2)
                                             should be AND, not a comma

How to get a jqGrid cell value when editing

I obtain edit value using javascript:


I hope this info useful for someone.

Accessing certain pixel RGB value in openCV

uchar * value =; //Pointer to the first pixel data ,it's return array in all values 
int r = 2;
for (size_t i = 0; i < img2.cols* (img2.rows * img2.channels()); i++)

        if (r > 2) r = 0;

        if (r == 0) value[i] = 0;
        if (r == 1)value[i] =  0;
        if (r == 2)value[i] = 255;


How to create a folder with name as current date in batch (.bat) files

If your locale has date format "DDMMYYYY" you'll have to set it this way:

set datestr=%date:~-4,4%%date:~3,2%%date:~-10,2%
mkdir %datestr%

ActiveXObject in Firefox or Chrome (not IE!)

ActiveX resolved in Chrome!
Hello all this is not the solution but the successful workaround and I have implemented as well.
This required some implementation on client machine as well that why is most suitable for intranet environment and not recommended for public sites. Even though one can implement it for public sites as well the only problem is end user has to download/implement solution.
Lets understand the key problem
Chrome cannot communicate with ActiceX
Solution: Since Chorme cannot communicate with ActiveX but still it can communicate with the API hosted on the client machine. So develop API using .Net MVC or any other technology so that through Ajax call it can communicate with the API and API communicate with the ActiveX object situated on the client machine. Since API also resides in Client machine that why there is no problem in communication. This API works as mediator between Chrome browser and ActiveX.
During API implementation you might encounter CORS issues, Use JSONP to deal with it.
Pictorial view of the solution Pictorial view of the solution

Other solution : Use URI Scheme like MailTo: or MS-Word to deal with outlook and word application. If your requirement is different then you can implement your customized URI Scheme.

How to use Switch in SQL Server

       @selectoneCount = case @Temp
       when 1 then (@selectoneCount+1)
       when 2 then (@selectoneCount+1)

   select  @selectoneCount 

from jquery $.ajax to angular $http

you can use $.param to assign data :

  url: "",
  method: "POST",
  data: $.param({"foo":"bar"})
  }).success(function(data, status, headers, config) {
   $ = data;
  }).error(function(data, status, headers, config) {
   $scope.status = status;

look at this : AngularJS + ASP.NET Web API Cross-Domain Issue

Which exception should I raise on bad/illegal argument combinations in Python?

I think the best way to handle this is the way python itself handles it. Python raises a TypeError. For example:

$ python -c 'print(sum())'
Traceback (most recent call last):
File "<string>", line 1, in <module>
TypeError: sum expected at least 1 arguments, got 0

Our junior dev just found this page in a google search for "python exception wrong arguments" and I'm surprised that the obvious (to me) answer wasn't ever suggested in the decade since this question was asked.

Javascript window.print() in chrome, closing new window or tab instead of cancelling print leaves javascript blocked in parent window

It looks like the problem had been resolved with the latest Chrome update... I'm running the Chrome Version 36.0.1964.4 dev-m.

I was limited too warning the user from closing print preview window by doing the following:

if(navigator.userAgent.toLowerCase().indexOf('chrome') > -1){   // Chrome Browser Detected?
    window.PPClose = false;                                     // Clear Close Flag
    window.onbeforeunload = function(){                         // Before Window Close Event
        if(window.PPClose === false){                           // Close not OK?
            return 'Leaving this page will block the parent window!\nPlease select "Stay on this Page option" and use the\nCancel button instead to close the Print Preview Window.\n';
    window.print();                                             // Print preview
    window.PPClose = true;                                      // Set Close Flag to OK.

Now the warning is no longer coming up after the Chrome update.