weixin_41889234的博客

let obj1 = { num: 1, sum(a, b, c, d) { console.log(this, "->", a, arguments); return this.num + a + b + (c ? c : 0) + (d ? d : 0); },};let obj2 = { num: 10,};Function.prototype.myBind = function () { let context = arguments[0], .