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

The shortest form for jQuery:

string = $.trim(string);

Link

Answer 2

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 3

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 4

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 5

This is probably not the fastest, and might violate what ".trim()" probably should really be, but I don't like RegExs (mainly because it takes so much time to figure out what they really mean/do) and I like having something that I know will work regardless of whether I have jQuery or not (not to mention the right version, since I tried $.trim(myVar) with jQuery 1.4.2 and it does not work), and will get rid of ALL extra spaces, not just at the end, rebuilding it like it should be:

function Trim(obj) {
    var coll = "";
    var arrObj = obj.split(' ');

    for (var i=0;i<arrObj.length;i++) {
        if (arrObj[i] == "") {
            arrObj.splice(i,1);  // removes array indices containing spaces
        }
    }
    //alert(arrObj.length);  // should be equal to the number of words
    // Rebuilds with spaces in-between words, but without spaces at the end
    for (var i=0;i<arrObj.length;i++) {
        if (arrObj[i] != "" && i != arrObj.length-1)
            coll += arrObj[i] + " ";
        if (arrObj[i] != "" && i == arrObj.length-1)
            coll += arrObj[i];
    }

    return coll;
}

Answer 6

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;
    }
}