function Parent() {
  this.money = '2億'
  this.eat = function () {
    console.log('吃飯')
  }
}

Parent.prototype.hobby = function () {
  console.log("旅行")
}


function Son(name, age) {
  this.name = name;
  this.age = age
}


Son.prototype = new Parent(); // 將Son的prototype對象指向一個Parent的實例。它相當于完全刪除了prototype 對象原先的值，然后賦予一個新值
/**
*
* 任何一個prototype對象都有一個constructor屬性，指向它的構造函數。
* 如果沒有"Son.prototype = new Parent();"這一行，Son.prototype.constructor是指向Son的；加了這一行以后，Son.prototype.constructor指向Parent。
*
*/
Son.prototype.constructor = Son

var son = new Son("小明", 18);
son.hobby()//旅行

function Parent() { }

Parent.prototype.hobby = function () {
  console.log("旅行")
}


function Son(name, age) {
  this.name = name;
  this.age = age
}

Son.prototype = Parent.prototype;
Son.prototype.constructor = Son;

let s = new Son();
s.hobby();//旅行

function Parent() { }

Parent.prototype.hobby = function () {
  console.log("旅行")
}

function Son(name, age) {
  this.name = name;
  this.age = age
}

// function Buffer(){} //空對象
// Buffer.prototype = Parent.prototype;
// Buffer.prototype.constructor = Buffer;
// Son.prototype = new Buffer();
// Son.prototype.constructor = Son;
// let s = new Son();
// s.hobby()

/**
* 對上述方法進行封裝
*/

function extend(Child, Parent) {
  function Buffer() { };
  Buffer.prototype = Parent.prototype;
  Buffer.prototype.constructor = Buffer;
  Child.prototype = new Buffer();
  Child.prototype.constructor = Child
}

extend(Son, Parent);
let s = new Son();
s.hobby()//旅行