String.prototype.left = function (n) { if (n > this.length) return this; return this.substr(0, n); } String.prototype.right = function(n) { if (n > this.length) return this; return this.substr(this.length-n, n); } And they would be used like this: alert("Hello".right(2)) // Yields lo alert("Hello".left(4)) // Yields Hell