Javascript OOP繼承

Question

我創建了這些對象及其方法。

var Door = function(no = 10) { 
    this.number = isNaN(no) ? 10 : no; 
} 

var Room = function(door) { 
    this.door = door instanceof Door ? door : new Door(); 
    this.name = 'Room'; 
} 

function MyRoom(){ 
    this.name = 'MyRoom'; 
} 
MyRoom.prototype = new Room(); 

function HerRoom() { 
    this.name = 'HerRoom'; 
} 
HerRoom.prototype = new Room(); 

var $myDoor = new Door(10); 
var $herDoor = new Door(5); 

var $myRoom = new MyRoom($myDoor); 
var $herRoom = new HerRoom($herDoor); 

console.log($myDoor, $myRoom.door); 
// $myDoor.number is 10 
// $myRoom.door.number is 10 

console.log($herDoor, $herRoom.door); 
// $herDoor.number is 5 
// $herRoom.door.number is 10 

我不知道我做錯了什麼，讓$myDoor == $myRoom.door，但，$herDoor != $herRoom.door。任何人都可以幫助我注意我的錯誤在哪裏？

更新：

因爲，我創建

​​

我期待那$herRoom.door.number等於$herDoor.number。因爲，

$herDoor instanceof Door // true; 

Answer 1

我不知道我做錯了什麼，讓$ myDoor == $ myRoom.door， 但是$ herDoor！= $ herRoom.door。

很簡單，因爲你給了var $herDoor = new Door(5);在初始化$herDoor其分配給5財產number。

改變構造函數調用的值會給你你想要

var $herDoor = new Door(10); 

道歉後期編輯輸出，似乎你都希望分配房間，以MyRoom的原型後，房間的構造函數將被調用。另外，由於您沒有將門對象傳遞給MyRoom，它永遠不會獲得此對象。

你需要做以下更改

function Door (no) { 
    this.number = isNaN(no) ? 10 : no; 
} 

function Room (door) { 
    this.door = door instanceof Door ? door : new Door(); 
    this.name = 'Room'; 
} 

function MyRoom(door){ 
    this.name = 'MyRoom'; Room.call(this, door); //door object is passed and Room constructor is invoked with it 
} 
MyRoom.prototype = Object.create(Room.prototype); 
function HerRoom(door) { 
    this.name = 'HerRoom'; Room.call(this, door);//door object is passed and Room constructor is invoked with it 
} 
HerRoom.prototype = Object.create(Room.prototype); 

var $myDoor = new Door(10); 
var $herDoor = new Door(5); 

var $myRoom = new MyRoom($myDoor); 
var $herRoom = new HerRoom($herDoor); 

console.log($myDoor, $myRoom.door); 
console.log($herDoor, $herRoom.door);