Here you can find the source of Contains( str )
String.prototype.Contains = function( str ) { return this.indexOf( str ) > -1; };
String.prototype.Contains = function( textToCheck ) return ( this.indexOf( textToCheck ) > -1 ) ;
String.prototype.containIgnoreCase = function (otherStr) { return this.toLowerCase().indexOf(otherStr.toLowerCase());
String.prototype.contains = function( s, index) { return this.indexOf(s,index||0) > -1;
String.prototype.contains = function() { var args = arguments; for (var i in args) { var str = args[i]; if (typeof str === "string" && this.indexOf(str) > -1) { return true; return false; ...