Try this script to get your browser language 

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-html --&gt;
&lt;script type=&quot;text/javascript&quot;&gt;
    var userLang = navigator.language || navigator.userLanguage; 
    alert (&quot;The language is: &quot; + userLang);
&lt;/script&gt;
&lt;!-- end snippet --&gt;

Cheers

The &quot;JavaScript&quot; way:

    var lang = navigator.language || navigator.userLanguage; //no ?s necessary

Really you should be doing language detection on the server, but if it&#39;s absolutely necessary to know/use via JavaScript, it can be gotten.

I&#39;m a little confused about the python `in` operator for sets.

If I have a set `s` and some instance `b`, is it true that `b in s` means &quot;_is there some element `x` in `s` such that `b == x` is `true`_&quot;?

Python&#39;s &quot;in&quot; set operator

I need a tool to compare 2 binaries. The files are quite large. Some freeware or trial tools I found on the Internet are not convenient to use for large files. Can you recommend me some tools?

Tool for comparing 2 binary files in Windows

&gt; **Possible Duplicate:**  
&gt; [JavaScript for detecting browser language preference](https://stackoverflow.com/questions/1043339/javascript-for-detecting-browser-language-preference)  

&lt;!-- End of automatically inserted text --&gt;

I want to detect the language of the browser that is entering my site, if it&#39;s En or Fr. So I can redirect to the En page or the other page.

Also, can I detect mobile language?

How to get the browser language using JavaScript

> Possible Duplicate: 
> <a href="https://stackoverflow.com/questions/1043339/javascript-for-detecting-browser-language-preference" target="_blank" rel="noopener noreferrer">JavaScript for detecting browser language preference</a>

I want to detect the language of the browser that is entering my site, if it's En or Fr. So I can redirect to the En page or the other page.
Also, can I detect mobile language?

I&#39;m trying to make a js code that works with multiple pages.
I&#39;m trying to use querySelectorAll() to obtain the elements form the DOM.

I need the elements to be ordered. In order to do that I may use xPath or selectors (I&#39;d prefer to use selectors but xPath is also ok). The problem is:  
Are the elements in the NodeList returned by querySelectorAll() ordered against the order that the tags appear in the HTML?




Note: I&#39;d like to add the tag: querySelectorAll

Using querySelectorAll(). Is the result returned by the method ordered?

I want to add codes inside disable() function to disable dragging and zooming in Google maps API v3 by clicking on &#39;disable&#39; button. 

    &lt;script type=&quot;text/javascript&quot;&gt;
       var map;

      function initialize() {
    var uluru = new google.maps.LatLng(21, 57);
    map = new google.maps.Map(document.getElementById(&quot;map&quot;), {
      zoom: 6,
      center: uluru,
      mapTypeId: google.maps.MapTypeId.HYBRID
    });
    }


    function disable(){

    }

    &lt;/script&gt;


    &lt;body onload=&quot;initialize()&quot; &gt;

	   &lt;input type=&quot;button&quot; id=&quot;next&quot; value=&quot;disableZoomDrag&quot; onclick=&quot;disable()&quot;&gt;

    &lt;/body&gt;


disable zooming dragging in Google maps by clicking on a button

What is the difference (if there is any) between

    x = Array()

and

    x = new Array()

Which one should I use?

Array() vs new Array()

# DO YOU KNOW SOME MORE BEST PRACTICES FOR CANVAS?? 

## Please add to this thread what you know, have learned, or have read online any and all Canvas best practices, tips/tricks for performance

With Canvas being still very new to internet, and no signs of it ever getting old that I can see in the future, there are not too many documented &quot;best practices&quot; or other really important tips that are a &#39;must know&#39; for developing with it in any one particular place. Things like this are scattered around and many times on lesser known sites. 

**There&#39;s so many things that people need to know about, and still so much to learn about too.** 

----------


I wanted to share some things to help people who are learning Canvas and maybe some who already know it quite well and am hoping to get some feedback from others about what they feel are some best practices or other tips and tricks for working with Canvas in HTML5. 

I want to start off with one I personally found to be quite a useful yet surprisingly uncommon thing for developers to do.

# 1. Indent your code

Just as you would any other time, in any other language whatever the case may be. It has been a best practice for everything else, and I have come to find that in a complex canvas app, things can get a little confusing when dealing with several different contexts and saved/restore states. Not to mention the code is just more readable and overall cleaner looking too. 

For example:

    ...
    // Try to tell me this doesn&#39;t make sense to do
    ctx.fillStyle = &#39;red&#39;;
    ctx.fill();
    ctx.save();
        if (thing &lt; 3) {
            // indenting
            ctx.beginPath();
                ctx.arc(2, 6, 11, 0, Math.PI*2, true);
            ctx.closePath();
            ctx.beginPath();
                ctx.moveTo(20, 40);
                ctx.lineTo(10, 200);
                ctx.moveTo(20, 40);
                ctx.lineTo(100, 40);
            ctx.closePath();
            ctx.save();
                ctx.fillStyle = &#39;blue&#39;
                ctx.fill();
            ctx.restore();
        } else { 
            // no indenting
            ctx.drawImage(img, 0, 0, 200, 200);
            ctx.save();
            ctx.shadowBlur();
            ctx.beginPath();
            ctx.arc(2, 60, 10, 0, Math.PI*2, false);
            ctx.closePath();
            ctx.fillStyle &#39;green&#39;;
            ctx.fill();
            ctx.restore();
        }
    ctx.restore();
    ctx.drawRect();
    ctx.fill();
    ...

Is the IF statement not easier and cleaner to read and know what is what immediately going on than the ELSE statement in this? Can you see what I&#39;m saying here? I think this should be a method that developers should continue to practice just as they would when writing plain &#39;ol javascript or any other language even.


# Use requestAnimationFrame instead of setInterval / setTimeout

setInterval and setTimeout were never intended to be used as animation timers, they&#39;re just generic methods for calling functions after a time delay.  If you set an interval for 20ms in the future, but your queue of functions takes longer than that to execute, your timer won&#39;t fire until after these functions have completed.  That could be a while, which isn&#39;t ideal where animation is concerned. **RequestAnimationFrame** is a method which tells the browser that an animation is taking place, so it can optimize repaints accordingly.  It also throttles the animation for inactive tabs, so it won&#39;t kill your mobile device&#39;s battery if you leave it open in the background.

Nicholas Zakas wrote a hugely detailed and informative [article about requestAnimationFrame](http://www.nczonline.net/blog/2011/05/03/better-javascript-animations-with-requestanimationframe/) on his blog which is well worth reading.  If you want some hard and fast implementation instructions, then [Paul Irish has written a requestAnimationFrame shim](http://paulirish.com/2011/requestanimationframe-for-smart-animating/) – this is what I&#39;ve used in every one of the Canvas apps I have made until recently.

## ACTUALLY

Even better than using requestAnimationFrame in place of setTimeout and setInterval, Joe Lambert has written a [NEW and improved shim](http://blog.joelambert.co.uk/2011/06/01/a-better-settimeoutsetinterval/) called requestInterval and requestTimeout, which he explains what issues exist when using requestAnimFrame.
You can view the [gist of the script](https://gist.github.com/1002116#file_request_interval.js).

## ACTUALLY x2

Now that all the browsers have caught up on the spec for this, there has been an [update to the requestAnimFrame() polyfill](http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating), one which will probably remain the one to use to cover all vendors. 


# Use more than one canvas 

A technique for animation-heavy games which [@nicolahibbert](https://twitter.com/nicolahibbert) wrote about in a [post of hers on optimizing Canvas games](http://nicolahibbert.com/optimising-html5-canvas-games/) mentions that it may be better to use multiple canvasses layered on top of one another rather than do everything in a single canvas. Nicola explains that &quot;drawing too many pixels to the same canvas at the same time will cause your frame rate to fall through the floor. Take Breakout for example. Trying to draw the bricks, the ball, the paddle, any power-ups or weapons, and then each star in the background – this simply won&#39;t work, it takes too long to execute each of these instructions in turn. By splitting the starfield and the rest of the game onto separate canvases, you are able to ensure a decent framerate.&quot;

## Render Elements Off-screen

I have had to do this for a few apps I&#39;ve made including [Samsung&#39;s Olympic Genome Project facebook app][1]. It&#39;s an extremely useful thing to know and to make use of whether it&#39;s needed or not. It decreases load time immensely, plus it can be a really useful technique to load images off screen since they can sometimes take a while.

    var tmpCanvas = document.createElement(&#39;canvas&#39;),
        tmpCtx = tmpCanvas.getContext(&#39;2d&#39;),
        img = document.createElement(&#39;img&#39;);
    
    img.onload = function() {
        tmpCtx.drawImage(thumbImg, 0, 0, 200, 200);
    };
    img.src = &#39;/some/image/source.png&#39;;

Notice that the src of the image is set after it is loaded. This is a key thing to remember to do too. Once the images are done loading and drawn into these temp canvases, you can then draw them to your main canvas by using the same ctx.drawImage(), but instead of putting the image as the first argument, you use &#39;tmpCtx.canvas&#39; to reference the temp canvas.


### Other tips, tricks and resources

 - **[Canvas test cases](http://philip.html5.org/tests/canvas/suite/tests/)**
 - **[Some more canvas and JS tests](http://kangax.github.com/jstests/)**
 - **[HTML5Rocks performance Improving](http://www.html5rocks.com/en/tutorials/canvas/performance/)**
 - **[requestAnimFrame to Optimize Dragging Events](http://blog.digitalbackcountry.com/2012/05/using-requestanimationframe-to-optimize-dragging-events/)

### Canvas has a back-reference

The 2d context has a back reference to it&#39;s associated DOM element:

    var ctx = doc.getElementById(&#39;canvas&#39;).getContext(&#39;2d&#39;);
    console.log(ctx.canvas);    // HTMLCanvasElement



I&#39;d love to hear more from other people on this. I am working on making a list of things that we should standardize to add a new section to my company&#39;s [Front-end Code Standards and Best Practices](http://na.standards.com/standards). I&#39;d love to get as much feedback on this as I can.


  [1]: http://www.facebook.com/samsunggenomeproject/app_197458140327772

HTML5 Canvas Performance and Optimization Tips, Tricks and Coding Best Practices

I have run into an odd situation. I&#39;m writing a JavaScript bookmarklet that will allow users to click and share external websites to our website very easily and quickly. It simply get&#39;s the title, page URL, and if they&#39;ve selected any text on the page, it grabs it too.

The problem is it doesn&#39;t work with external domains for some reason, so if we use it internally we end up with a share window with the URL formatted like this:

http://internaldomain.com/sharetool.php?shareid=http://internaldomain.com/anotheroddpage.html&amp;title=....

That works just fine, BUT if we try to use an external domain and end up with a URL formatted like this:

http://internaldomain.com/sharetool.php?shareid=http://externaldomain.com/coolpagetoshare.html&amp;title=...

Then we get a *Forbidden Error* on our page and can&#39;t load it... If we manually remove the `http://` from the externaldomain address, it loads just fine again.

So.. I&#39;m thinking the best solution to get around this problem is to modify the JavaScript bookmarklet to remove the `http` as it&#39;s loading the window. Here is how my current bookmarklet looks:

    javascript:var d=document,w=window,e=w.getSelection,k=d.getSelection,x=d.selection,s=(e?e():(k)?k():(x?x.createRange().text:0)),f=&#39;http://internaldomain.com/sharetool.php&#39;,l=d.location,e=encodeURIComponent,u=f+&#39;?u=&#39;+e(l.href)+

As you can see, `e(l.href)` is where the URL is passed.

How can I modify that so it removes the external domains `http://`?



Content Type	Original Author	Original Content on Stackoverflow
Question	ghs.alshareef	View Question on Stackoverflow
Solution 1 - Javascript	Alim Ul Gias	View Answer on Stackoverflow
Solution 2 - Javascript	zzzzBov	View Answer on Stackoverflow

How to get the browser language using JavaScript

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Tool for comparing 2 binary files in Windows

Python's "in" set operator

Attributions