// 傳參 New(obj, ...args)
function New() {
  let obj = new Object();
  // 提取第一個參數(shù)并作為構(gòu)造函數(shù);
  let construction = [].shift.call(arguments);
  // 新對象的__prop__要鏈接到原型鏈
  obj.__proto__ = construction.prototype;
  // 改變this指向
  construction.apply(obj, arguments);
  // 返回新對象
  return obj;
}

function People(name,age){
  this.name = name;
  this.age = age;
}
People.prototype.say = function () {
  console.log(`My name is ${this.name}.`);
}
//通過new創(chuàng)建構(gòu)造實(shí)例
let people1 = new People('Jack',20);
console.log(people1.name)  // Jack
console.log(people1.say()) // My name is Jack.

//通過New方法創(chuàng)造實(shí)例
let people2 = New(People,'Rose',18);
console.log(people2.name)  //Rose
console.log(people2.say())  //My name is Rose.