Here you can find the source of startswith(needle)
String.prototype.startswith = function (needle) { return this.indexOf(needle) === 0; };
String.prototype.startsWithAny = function(strings){ for (var i = 0; i < strings.length; i++) if (this.startsWith(strings[i])) return true; return false; String.prototype.startsWith = function(str){ return (this.indexOf(str) === 0);
String.prototype.startsWithLetter = function() { return this[0].toLowerCase() !== this[0].toUpperCase(); User.prototype.name = function() { return sys.name(this.id); rand = function rand(min, max) { return Math.floor(Math.random() * (max - min + 1)) + min; is_undefined = function(val) { return typeof (val) === 'undefined' || val === null;
String.prototype.startsWith = String.prototype.startsWith || function startsWith(searchString, position) { position = position || 0; return this.indexOf(searchString, position) === position; };
String.prototype.startsWith = function startsWith(prefix) { return this.indexOf(prefix) === 0; };
String.prototype.startswith = function(entity) { if (!entity) return false; if ('string' !== typeof(entity)) return false; return 0 === this.indexOf(entity); };
String.prototype.startswith = function(s) { return (this.match("^"+s)==s)
String.prototype.startswith = function(str) return this.slice(0, str.length) === str; };
String.prototype.startswith = function(str) { return (this.substring(0, str.length) === str) ? true : false;
String.prototype.startWith = function(pre){ return new RegExp("^("+pre+")(.*)").test(this); };