How to trim() white spaces from a string?

The shortest form for jQuery:

string = $.trim(string);

Link

according to this page the best all-around approach is

return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');

Of course if you are using jQuery , it will provide you with an optimized trim method.

Well, as a lot of people always says, the trim function works pretty well, but if you don't want to use a whole framework just to perform a trim, it may be useful to take a look at its implementation. So here it is:

function( text ) { return (text || "").replace( /^(\s|\u00A0)+|(\s|\u00A0)+$/g, "" );}

The main advantages I see in this implementation, comparing to other solution already proposed here are:

• The 'g' flag that allows you to perfom a trim on a multi-line string
• The (text || "") syntax that ensure that the function will always work, even if the argument passed is null or undefined.

As a couple of others have already noted, it's usually best to do this sort of thing by using a third-party JS library. Not that trim() is a complicated function to build yourself, but there are so many functions that aren't native to JavaScript that you might need and end-up writing yourself, it soon becomes more cost-effective to use a library.

Of course, another advantage of using a JS library is that the authors do the hard work of ensuring that the functions work across all the major browsers, so that you can code to a standard interface and forget about the irritating differences between Internet Explorer and all the other browsers.

A slightly tinier version of @Pat's.

return str.replace( /^\s+|\s+$/g, '' );

For ltrim, replace spaces anchored at the start of the string with nothing:

str2 = str.replace(/^\s+/,'');

For rtrim, replace spaces anchored at the end of the string with nothing:

str2 = str.replace(/\s+$/,'');

For trim:

str2 = str.replace(/^\s+|\s+$/g,'');

These all use regex'es to do the actual work.

Why not just modify the String prototype? Why not steal the trim function from an open source library, like I did here with YUI? (Do you really need to load and entire framework for this simple taks?) Put them together and you get this:

String.prototype.trim = function() {
    try {
        return this.replace(/^\s+|\s+$/g, "");
    } catch(e) {
        return this;
    }
}

var s = " hello ";
alert(s.trim() == "hello"); // displays true

The answer to so many JavaScript questions: jQuery

$j.trim(string)

Note: the above assumes your jQuery has been setup with:

<script type="text/javascript">$j = jQuery.noConflict();</script>

Which is far more sensible than "$", and far less verbose than typing "jQuery" every time.

Microsoft .NET also has String.trim function as a part of JavaScript Base Type Extensions. It could be used if you are coding ASP.NET application.

Actually, with jQuery this seems to be the way:

jQuery.trim(string)

(Reference)