如何对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。我正在尝试从抽象构造函数 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

吉斯菲德尔

Answer 1

您可以使用

call方法并在PlayerShip函数中传递parameters。

Ship.call(this, x,y);

调用 parent's 构造函数会初始化对象本身，这是通过每次实例化完成的(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);