String.extract.js

/*
 * Idea from http://james.padolsey.com/javascript/stringprototypeextract/
 */

String.implement({

	extract: function(regex, n){
		n = (n===undefined) ? 0 : n;
		if (!regex.global) return this.match(regex)[n] || '';
		var match, extracted = [];
		while (match = regex.exec(this)) extracted.push(match[n] || '');
		return extracted;
	}

});