jQuery Forum

While I think using the native trim() makes sense if it's available, I wonder about the need for the Levithan enhancement. How representative of a use case is trimming the Magna Carta? Seems most of the time the text to be trimmed would be much smaller than 27,600 characters.

Have you noticed performance problems with jQuery's $.trim()? Have you isolated and benchmarked it? If so, it would probably be helpful to see your tests.

Cheers,

--Karl

Also, if you've got a string that long, it's probably an HTML string.  You can safely $(html) it anyway...unless you bust the heap!

If the new code I've committed is overkill, then how about this simple improvement then:

     trim: function( text ) {
        if ( typeof String.trim === "function" ) {
            return ( text || "" ).trim();
        }
        return (text || "").replace( /^\s\s*/, "" ).replace( /\s\s*$/, "" );
    },

@Travis, you did (before) premature optimization, which is "the source of all evil" ... But, now when we have a proper javascript we can optimize.

var thtrim3 = typeof "".trim === "function" ? function( text ) {
            return ! text ? "" : text.trim();
        }
: function ( text ) {
        return ! text ? "" : text.replace( /^\s\s*/, "" ).replace( /\s\s*$/, "" );
    };

Above you have replaced rtrim in  "my" method and arrived to above faster version. Which is OK. I am wondering will it trim-out "\u00A0" , as  current offical regexp does ?

rtrim = /^(\s|\u00A0)+|(\s|\u00A0)+$/g ; // current jQuery

I am also wondering will it be able to cache the regular expressions used ? Also, is this extreme optimization necessary? In real programs, you will never find string trimming called 5000 times in a tight loop. Or strings which are longer than approx 1024. I am pretty sure that in the region of string length < 1024, one will see very little speed difference between browsers, using any of the trims from here. And one will se negligible difference v.s. all that repeated with the current jQuery.trim() .

// replacement for trimming Very Large Strings
// for hosts which do not support ES5 "".trim()
jQuery.trim = typeof "".trim === "function" ? 
function( text ) { return ! text ? "" : text.trim(); } 
: function (str) {
// http://blog.stevenlevithan.com/archives/faster-trim-javascript
	var	str = str.replace(/^[\s\xA0]*/, ''),
		ws = /[\s\xA0]/, i = str.length;
	while (ws.test(str.charAt(--i)));
	return str.slice(0, i + 1); 
}