What is the best way to trim() in javascript

Question

The question says it all; JS doesn't seem to have a native trim() method.

Answer 1

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.

Answer 2

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.

Answer 3

A slightly tinier version of @Pat's.

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

Answer 4

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.

Answer 5

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.

Answer 6

Actually, with jQuery this seems to be the way:

jQuery.trim(string)

(Reference)

Answer 7

The shortest form for jQuery:

string = $.trim(string);

Link

Answer 8

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.

Answer 9

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.

Answer 10

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

Answer 11

I use this.

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

Answer 12

Use Ariel Flesler's fast trim function:

// Licensed under BSD
function myBestTrim( str ){
 var start = -1,
  end = str.length;
 while( str.charCodeAt(--end) < 33 );
 while( str.charCodeAt(++start) < 33 );
 return str.slice( start, end + 1 );
};

My solution, though, would be this (because the String object in Firefox 3.5 and above already has a trim method):

String.prototype.trim = String.prototype.trim || function () {
    var start = -1,
        end   = this.length;

    while( this.charCodeAt(--end) < 33 );
    while( this.charCodeAt(++start) < 33 );

    return this.slice( start, end + 1 );
};

Answer 13

I use this:

Work with functions.

 function trim($) { 
                return (typeof $ == "function" ? $() : $).replace(/[\s]*/g,"")
        }

        code example: 

        trim((function(){ return "a  b"})) // ab

        trim(" a  b") //ab

Answer 14

You can use following ...

function trim(str) {
try{
    if(str && typeof(str) == 'string'){
        return str.replace(/^\s*|\s*$/g,"");
    } else {
        return '';
    }
} catch(e) { return str;  }