Trim string in JavaScript

How do I remove all whitespace from the start and end of the string?

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,' ');};


Stack Overflow Q#498970, score: 941