Question

请帮我修复我的代码。在我的游戏中存在敌人物体和玩家物体。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);

但是所有对象都没有属性：xCoords，yCoords

JSFIDDLE

Answer 1

您可以使用call方法并在parameters函数中传递PlayerShip。

Ship.call(this, x,y);

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

＆＃13;

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);

＆＃13;

如何使用抽象构造函数来构建游戏对象？

1 个答案: