Here you can find the source of trimLeft()
String.prototype.trimLeft = String.prototype.trimLeft || function() { return this.replace(/^\s+/,''); };
String.prototype.ltrim = function(){ var res = this; while (res.substring(0, 1) == " ") { res = res.substring(1, res.length); return res;
String.prototype.ltrim=function() {return this.replace(/^\s+/,'');}
String.prototype.ltrim = function(ch) { var r = new RegExp("^{0}+".format(ch || "\\s")); return this.replace(r, ""); };
String.prototype.ltrim = function (charlist) { charlist = !charlist ? ' \\s\u00A0' : (charlist + '').replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '$1'); var re = new RegExp('[' + charlist + ']+$', 'g'); return this.replace(re, ''); };
String.prototype.trimLeft = function() { return this.replace(/^\s+/, ''); };
String.prototype.trimLeft = function (character) { character = character || ' '; return this.replace(new RegExp('^[' + character + ']+'), ""); };
String.prototype.trimLeft = function(charlist = '\s') { return this.replace(new RegExp('^[' + charlist + ']+'), ''); };
String.prototype.lTrim = function() return this.replace(/(^[\\s]*)/g, "");
String.prototype.lTrim = function(){ str = this; var i; for(i=0;i<str.length;i++) if(str.charAt(i)!=" "&&str.charAt(i)!=" ")break; str=str.substring(i,str.length); return str; ...