javascript - 如何为游戏对象使用抽象构造函数？

Question

请帮助修复我的代码。在我的游戏中存在敌人对象和玩家对象。它们具有相同的属性:xCoord、yCoord。我试图从抽象构造函数 Ship() 继承这些属性:

var player,
    enemies = [],
    enemiesCntInit = 10;

function Ship(x, y) {
  this.xCoord = x;
  this.yCoord = y;
};

function PlayerShip(x, y) {
  this.petrol = 100;
};  

function EnemyShip(x, y) {  
  this.color = 'red';
}; 

PlayerShip.prototype = Object.create(Ship.prototype);


player = new PlayerShip(100, 100); 

for(var i = 0; i < enemiesCntInit; i++) {
  enemies.push(new EnemyShip(0, 0));
}

console.log(player);
console.log(enemies);

但不是所有对象都有属性:xCoords、yCoords

JSFIDDLE

Answer 1

您可以使用call 方法并在PlayerShip 函数中传递您的参数。

Ship.call(this, x,y);

调用父级构造函数初始化对象本身，这是在每次实例化时完成的(每次构造它时都可以传递不同的参数)。

var player,
    enemies = [],
    enemiesCntInit = 10;

function Ship(x, y) {
  this.xCoord = x;
  this.yCoord = y;
};

function PlayerShip(x, y) {
  Ship.call(this, x,y);
  this.petrol = 100;
};  

function EnemyShip(x, y) {  
  Ship.call(this, x,y);
  this.color = 'red';
}; 

PlayerShip.prototype = Object.create(Ship.prototype);


player = new PlayerShip(100, 100); 

for(var i = 0; i < enemiesCntInit; i++) {
  enemies.push(new EnemyShip(0, 0));
}

console.log(player);
console.log(enemies);