# 手写 new 操作符

/**
 * Car
 * @descript 定义一个构造函数
 * @param {string} name
 * @param {string} color
 */
function Car(name, color) {
    this.name = name;
    this.color = color;
}

Car.prototype.sayInfo = function () {
  console.log(`The color of the ${this.name} is ${this.color}`);
}

Car.prototype.sayName = function () {
  console.log(`My name is ${this.name}`);
}

var car = new Car('bwm', 'red');
console.log(car.name) // bwm
console.log(car.sayName()) // My name is bwm
console.log(car.sayInfo()) // The color of the bwm is red

// 调用内置函数
var array = new Array(); // []
var obj = new Object(); // {}

// new操作符的简易实现
function myNew(fn) {
    var obj = {};
    obj.__proto__ = fn.prototype;
    // 这里执行fn的constructor，this指向obj 并将传入的参数一并传入
    var result = fn.apply(obj, Array.prototype.slice.call(arguments, 1));
    // 验证返回的是否object
    /** 这里应该严格注意 typeof返回object的其实还有null 简易版未做处理 **/
    return typeof result === "object" ? result : obj;
}


function Car(name, color) {
    this.name = name;
    this.color = color;
}

Car.prototype.sayInfo = function () {
  console.log(`The color of the ${this.name} is ${this.color}`);
}

Car.prototype.sayName = function () {
  console.log(`My name is ${this.name}`);
}

var car = myNew(Car, 'bwm', 'red');
console.log(car.name) // bwm
console.log(car.sayName()) // My name is bwm
console.log(car.sayInfo()) // The color of the bwm is red

// 调用内置函数
var array = new Array(); // []
var obj = new Object(); // {}