lovecoding
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Web1020


			
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    <script>
        // 第一步向Function.prototype上添加一个bind2方法
        // Function.prototype.bind2 = function (obj,...arg) {
        //     // 返回一个函数
        //     let that = this;
        //     return function () {
        //         // that.call(obj);
        //         // that.apply(obj,arg);
        //         that.call(obj,...arg);
        //     }
        // }

        Function.prototype.bind2 = function (obj) {
            // 返回一个函数
            var that = this;
            // console.log(arguments.slice(1));
            // console.log(arguments);
            // console.log(Array.from(arguments));
            // var arg = Array.from(arguments);
            var arg = Array.prototype.slice.call(arguments,1);
            return function () {
                // that.call(obj);
                // that.apply(obj,arg);
                that.apply(obj,arg);
            }
        }


        function foo(x,y) {
            console.log(this.a,x,y)//hello
        }
        var obj = {
            a: "hello"
        }


        var foo2 = foo.bind2(obj,1,2);
        foo2()


    </script>
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