参考回答：
bind（）方法，创建一个新函数，当这个新函数被调用时，bind（）的第一个参数将作为它运行时的this，之后的一序列参数将会在传递的实参前传入作为它的参数
Function.prototype.bind2 = function (context) {if (typeof this !== "function") {throw new Error("Function.prototype.bind - what is trying to be bound is not callable");}var self = this;var args = Array.prototype.slice.call(arguments, 1);var fNOP = function () {};var fbound = function () {self.apply(this instanceof self ? this : context, args.concat(Array.prototype.slice.call(arguments)));}fNOP.prototype = this.prototype;fbound.prototype = new fNOP();return fbound;}
