call & bind 源码理解

myCall

Function.prototype.myCall = function (context,...args) {
 context[this.name] = this;
 return context[this.name](...args);
}

测试

const foo = {
 name :"Jack",
 hi(str){
   console.log("this",this)
   console.log('hellow ', this.name, str)
 }
}
const bar = { name: "Lucy" };

foo.hi.myCall(bar, "call");
// hellow  Lucy call

myBind

Function.prototype.myBind = function (context) {
  return (...args) => this.call(context, ...args);
}

测试

const foo = {
  name :"Jack",
  hi(str){
    console.log("this",this)
    console.log('hellow ', this.name, str)
  }
}
const bar = { name: "Lucy" };

foo.hi.myBind(bar,"bind")("bind");
// hellow  Lucy bind