JavaScript String – How to Trim Specific Characters from the End

All browsers since IE9+ have trim() method for strings.

" \n test \n ".trim(); // returns "test" here

For those browsers who does not support trim(), you can use this polyfill from MDN:

if (!String.prototype.trim) {
    (function() {
        // Make sure we trim BOM and NBSP
        var rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
        String.prototype.trim = function() {
            return this.replace(rtrim, '');
        };
    })();
}

That said, if using jQuery, then $.trim(str) is always available, which handles undefined/null as well.

See this:

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

String.prototype.ltrim=function(){return this.replace(/^\s+/,'');};

String.prototype.rtrim=function(){return this.replace(/\s+$/,'');};

String.prototype.fulltrim=function(){return this.replace(/(?:(?:^|\n)\s+|\s+(?:$|\n))/g,'').replace(/\s+/g,' ');};

Why not just use substring... string.substring(0, 7); The first argument (0) is the starting point. The second argument (7) is the ending point (exclusive). More info here.

var string = "this is a string";
var length = 7;
var trimmedString = string.substring(0, length);