Question

JS的新手，我无法弄清楚如何运行新创建的对象的构造函数。

var player = new Player();
alert(player.getPosition()); // [ undefined, undefined ]

function Player()
{
    //afaik the x & y vars should fill when creating a new Player object.
    var x = Math.floor((Math.random() * 800) + 1), 
        y = Math.floor((Math.random() * 800) + 1);
}

Player.prototype.getPosition = function()
{
    return [this.x, this.y];
}

Answer 1

问题是您没有将x和y分配给Player的实例。试试这个

function Player()
{
    this.x = Math.floor((Math.random() * 800) + 1);
    this.y = Math.floor((Math.random() * 800) + 1);
}

Answer 2

试试这个：

  function Player()
  {
//afaik the x & y vars should fill when creating a new Player object.
 this.x = Math.floor((Math.random() * 800) + 1); 
 this.y = Math.floor((Math.random() * 800) + 1);
   }

构造函数不工作？

2 个答案: