[UglifyJS2][1], used by the jQuery project.


  [1]: https://github.com/mishoo/UglifyJS2

## Active

* [Closure Compiler][1]
* [UglifyJS2][2]

## Deprecated

* [YUI Compressor][3]
* [UglifyJS][4]

---

Google Closure Compiler generally achieves smaller files than YUI Compressor, particularly if you use the advanced mode, which looks worryingly meddlesome to me but has worked well on the one project I&#39;ve used it on: 

Several big projects use UglifyJS, and I&#39;ve been very impressed with it since switching.


  [1]: https://developers.google.com/closure/compiler/
  [2]: https://github.com/mishoo/UglifyJS2
  [3]: http://developer.yahoo.com/yui/compressor/
  [4]: https://github.com/mishoo/UglifyJS/

[JavaScript Minifier](http://javascript-minifier.com) gives a good API you can use programatically:

    curl -X POST -s --data-urlencode &#39;input=$(function() { alert(&quot;Hello, World!&quot;); });&#39; http://javascript-minifier.com/raw


Or by uploading a file and redirecting to a new file:

    curl -X POST -s --data-urlencode &#39;input@ready.js&#39; http://javascript-minifier.com/raw &gt; ready.min.js

Hope that helps.


If you are using PHP you might also want to take a look at [minify][1] which can minify and combine JavaScript files. The integration is pretty easy and can be done by defined groups of files or an easy query string. Minified files are also cached to reduce the server load and you can add expire headers through minify.


  [1]: http://code.google.com/p/minify/

There are several you can use/try:

* [YUI compressor][1]
* [jsmin][2]
* [Microsoft Ajax minifier][3] (has hypercrunching)


[1]:http://developer.yahoo.com/yui/compressor/
[2]:http://www.crockford.com/javascript/jsmin.html
[3]:http://www.asp.net/ajaxLibrary/AjaxMinDocumentation.ashx

Pretty Diff - http://prettydiff.com/?m=minify

Sometimes i use this: http://closure-compiler.appspot.com/home

This tool: &lt;a href=&quot;https://jscompressor.com&quot;&gt;jscompressor.com&lt;/a&gt; is pretty good.

[YUI minifier][1]

  [1]: http://developer.yahoo.com/yui/compressor/

I want to initialize a String in Java, but that string needs to include quotes; for example: `&quot;ROM&quot;`. I tried doing:

    String value = &quot; &quot;ROM&quot; &quot;;

but that doesn&#39;t work. How can I include `&quot;`s within a string?

How to enter quotes in a Java string?

I&#39;m having a devil of a time finding a comparison of the different ways to query for a single item, and when to use each.

Does anyone have a link that compares all these, or a quick explanation as to why you would use one over the other?  Are there still more operators that I am unaware of?

Thank you.

Entity Framework 4 Single() vs First() vs FirstOrDefault()

What JavaScript minifier do you recommend?

Is there a good JavaScript minifier?

<p>What JavaScript minifier do you recommend?</p>


In his book &lt;a href=&quot;http://www.stevesouders.com/blog/2009/04/23/even-faster-web-sites/&quot;&gt;Even Faster Web Sites&lt;/a&gt; Steve Sounders writes that a simple way to improve the performance of a loop is to decrement the iterator toward 0 rather than incrementing toward the total length (*actually the chapter was written by Nicholas C. Zakas*). This change can result in savings of up to 50% off the original execution time, depending on the complexity of each iteration. For example:

    var values = [1,2,3,4,5];
    var length = values.length;
    
    for (var i=length; i--;) {
       process(values[i]);
    }

This is nearly identical for the `for` loop, the `do-while` loop, and the `while` loop.

I&#39;m wondering, what&#39;s the reason for this? **Why is to decrement the iterator so much faster?** (I&#39;m interested in the technical background of this and not in benchmarks proving this claim.) 

---
EDIT: At first sight the loop syntax used here looks wrong. There is no `length-1` or `i&gt;=0`, so let&#39;s clarify (I was confused too).

Here is the general for loop syntax:

    for ([initial-expression]; [condition]; [final-expression])
       statement

- *initial-expression* - `var i=length`
    
 This variable declaration is evaluated first. 

- *condition* - `i--`
 
 This expression is evaluated before each loop iteration. It will decrement the variable before the first pass through the loop. If this expression evaluates to `false` the loop ends. In JavaScript is `0 == false` so if `i` finally equals `0` it is interpreted as `false` and the loop ends.

- *final-expression*

 This expression is evaluated at the end of each loop iteration (before the next evaluation of *condition*). It&#39;s not needed here and is empty. All three expressions are optional in a for loop.

The for loop syntax is not part of the question, but because it&#39;s a little bit uncommon I think it&#39;s interesting to clarify it. And maybe one reason it&#39;s faster is, because it uses less expressions (the `0 == false` &quot;trick&quot;).

JavaScript loop performance - Why is to decrement the iterator toward 0 faster than incrementing

I&#39;m writing a Greasemonkey script for a site which at some point modifies `location.href`.

How can I get an event (via `window.addEventListener` or something similar) when `window.location.href` changes on a page? I also need access to the DOM of the document pointing to the new/modified url.

I&#39;ve seen other solutions which involve timeouts and polling, but I&#39;d like to avoid that if possible.

Event when window.location.href changes

I’d like to know if standard JS provides a way of splitting a string straight into a set of variables during their initial declaration. For example in Perl I would use:

```perl
my ($a, $b, $c) = split &#39;-&#39;, $str;
```

In Firefox I can write

```js
var [a, b, c] = str.split(&#39;-&#39;);
```

But this syntax is not part of the ECMAScript 5th edition and as such breaks in all other browsers. What I’m trying to do is avoid having to write:

```js
var array = str.split(&#39;-&#39;);
var a = array[0];
var b = array[1];
var c = array[2];
```

Because for the code that I’m writing at the moment such a method would be a real pain, I’m creating 20 variables from 7 different splits and don’t want to have to use such a verbose method.

Does anyone know of an elegant way to do this?

Split a string straight into variables

Once the user is on my page, I do not want him to refresh the page.

1. Anytime, the user hits &lt;kbd&gt;F5&lt;/kbd&gt; or refresh button on top. He should get an alert saying 

   &gt; You cannot refresh the page. 

2. Also if the user opens a new tab and tries to access the same url in prev tab he should get an alert 

   &gt; You cannot open same page in 2 tabs

Anyway I can do this using JavaScript or jQuery? Point one is really important.

Prevent any form of page refresh using jQuery/Javascript

Is there any way to get the previous URL in JavaScript?  Something like this:

    alert(&quot;previous url is: &quot; + window.history.previous.href);

Is there something like that?  Or should I just store it in a cookie?  I only need to know so I can do transitions from the previous URL to the current URL without anchors and all that.

How to get the previous URL in JavaScript?

Single Page Javascript Application
----------

I have built a sophisticated ajax-driven single page webapp that uses a RESTful backend web service serving JSON. The javascript is split into many different files, each file representing some sort of feature or component.

While the service has been in *alpha* testing, I&#39;ve just be serving all these files separately without minification. But now that I&#39;d like to launch a *beta* version, I really need to combine files, minify them, and version them. I want to add this to my build process, using Maven.

Javascript File Types
-------------
I&#39;m using the following &quot;types&quot; of javascript files, of which #3 and #4 are my concerns:

1. External files, such a jquery and jquery-ui served from the Google CDN. Rarely change these versions, can be handled manually.
2. Jquery plugins that I&#39;m hosting myself, such as fullcalendar or ui-layout. Again, I rarely update these to new versions and can handle it manually.
3. Application-wide javascript code. Custom javascript that is spread across many files and can change occasionally. All of these files need to be loaded for the app to work.
4. Feature-specific javascript code. Custom javascript that is loaded on demand when a specific feature is requested. This code can change quite frequently and is not loaded at startup.

Build Objectives
-----

I&#39;d like to do the following during my build process:

* Concatenate all type 3 javascript files together, minify them, and save as a single file with a version number. For instance: `app-2.0.6.min.js`, where 2.0.6 is the maven project version.
* All type 4 files should be individually minified and saved as separate files with version numbers in the name. For instance: `feature-abc-56ab32de29.min.js`, where 56ab32de29 is the version number of that specific file.
* Update HTML files with `&lt;script&gt;` tags to point to javascript files with the correct version numbers.
* Update Javscript files that load type 4 feature javascript files to point to the right versions.

Questions
-----

* Is there a maven plugin that will assist with the concatenation?

* Is there a maven plugin that will assist with the minification? Ideally, I&#39;d like to use Google Closure Compiler, but would work with others if simpler.

* Is there a maven plugin that will assist with the versioning? 

* Is there a way to have the type 4 javascript files have independent version numbers? Ideally, if a file doesn&#39;t change between version 2.0.5 and 2.0.6, there is no need for users to download a new version and their cached version would work fine. I&#39;m using GIT for source control, so would there be a way to use a file&#39;s GIT hashcode for versioning?

* Is there a solution that will compress the javascript that is inline in regular HTML files without killing the HTML?

* Is there a solution that will compress and version my CSS files as well?


Maven plugin for versioning and minifying javascript

I know you _can_ minify PHP, but I&#39;m wondering if there is any point. PHP is an interpreted language so will run a little slower than a compiled language. My question is: would clients see a visible speed improvement in page loads and such if I were to minify my PHP?

Also, is there a way to compile PHP or something similar?


Is there a point to minifying PHP?

Is there a plugin, add-on, Greasemonkey script or something similar (at worst, an easy to use proxy?) that automatically **unminifies** the Javascript files included on a site?

I know about e.g. [jsbeautifier.org](http://jsbeautifier.org/) but doing this externally doesn&#39;t allow me to set breakpoints in the unminified code, for example.

Typical use cases for me:

 - Analysing and learning from complex web frontends.
 - Debugging Greasemonkey scripts which interact with the existing code.

I&#39;m primarily interested in a solution that works with Firebug, but if there&#39;s something for the dev tools of Chrome or Opera, I&#39;d like to hear about it as well.


Is there a plugin that allows me to automatically unminify the Javascript included on a site?

I am looking for a php script or class that can minify my php page html output like google page speed does.

How can I do this?

How to minify php page html output?

Is there any module in NodeJS to concatenate and minify JavaScript files?

Content Type	Original Author	Original Content on Stackoverflow
Question	user160820	View Question on Stackoverflow
Solution 1 - Javascript	Andreas Hofmann	View Answer on Stackoverflow
Solution 2 - Javascript	Tim Down	View Answer on Stackoverflow
Solution 3 - Javascript	chilts	View Answer on Stackoverflow
Solution 4 - Javascript	2ndkauboy	View Answer on Stackoverflow
Solution 5 - Javascript	Kris van der Mast	View Answer on Stackoverflow
Solution 6 - Javascript	austincheney	View Answer on Stackoverflow
Solution 7 - Javascript	Filipe Costa	View Answer on Stackoverflow
Solution 8 - Javascript	MartinPalermo	View Answer on Stackoverflow
Solution 9 - Javascript	tom	View Answer on Stackoverflow

Is there a good JavaScript minifier?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Active

Deprecated

Solution 3 - Javascript

Solution 4 - Javascript

Solution 5 - Javascript

Solution 6 - Javascript

Solution 7 - Javascript

Solution 8 - Javascript

Solution 9 - Javascript

Entity Framework 4 Single() vs First() vs FirstOrDefault()

How to enter quotes in a Java string?

Attributions