手写bind

Function.prototype.mybind = function (target) {
      //target:改变返回函数执行时的this指向
      var obj = target || window;
      console.log(arguments,"arguments")
      var args = [].slice.call(arguments, 1); //获取bind时传入的绑定实参
      var args1 = [].slice.call(arguments, 0); //获取bind时传入的绑定实参
      console.log(args,"args")
      console.log(args1,"args1")
      var self = this; //要bind的函数
      console.log(self,"self")
      var _fn = function () {
        var _args = [].slice.call(arguments, 0); //新函数执行时传递的实际参数
        console.log(_args,"_args")
        return self.apply(obj, args.concat(_args));
      }
      return _fn
    }
    var name = 'fangfang';
    var obj = {
      name: 'geyao'
    };
    function fn(a, b, c) {
      console.log(a + b + c + this.name);
      return a + b + c + this.name
    };
    fn.mybind(obj,"我的","老婆","是")(); // 我的老婆是geyao