Question

我也是javascript oop和游戏编程的初学者（！）。在这里，我用方法创建了一个游戏玩家。但该方法返回undefined。为什么？，

bobsGame = {};

bobsGame.player  = function(which){
  this.which = which;
  this.rollDice = function () {
    diceVal = Math.floor(Math.random() * 6 + 1);
    console.log(diceVal);
    return diceVal;
  }
}

var player1 = new bobsGame.player('player1');

然后在标记中......

$('#roll-dice-btn-1').click(function(){
  bobsGame.player1.rollDice();
});

Answer 1

您的班级中没有bobsGame.player1，您只是为变量player1实例化了一个新实例？

var player1 = new bobsGame.player('player1');

$('#roll-dice-btn-1').click(function(){
    player1.rollDice();
});

FIDDLE

Answer 2

您的来电应该是player1.rollDice()

  $('#roll-dice-btn-1').click(function(){
    player1.rollDice();
  });

您对bobsGame对象的player属性与实际创建的player1对象感到困惑。

Answer 3

这可能会更好一点

bobsGame.player1 = new bobsGame.player('player1');

Answer 4

你可以玩这样的结构：

bobsGame = function(opts) {
    this.player = opts.player;
    this.diceVal = 0;
}

bobsGame.prototype.rollDice  = function(){
    this.diceVal = Math.floor(Math.random() * 6 + 1);
}

在您的主文件中：

var player1 = new bobsGame({player: 'player1'});
$('#roll-dice-btn-1').click(function(){
    player1.rollDice();
    console.log(player1.diceVal);
});

JsFiddle

Answer 5

你的问题很轻微。它在您的课程中找不到bobsGame.player1。所以改变这样，它会工作正常..

bobsGame.player  = function(which){
    this.which = which;

    this.rollDice = function(){
        diceVal = Math.floor(Math.random() * 6 + 1);
        console.log(diceVal);
        return diceVal;
    }
}


     var player1 = new bobsGame.player('player1');
    player1.rollDice();

Answer 6

bobsGame.player1未定义，因为player1未在对象bobsGame中声明。

如果您想在player1对象中创建bobsGame作为键，则必须使用bobsGame.player1 = new bobsGame.player('player1');。所以你的代码看起来像： bobsGame = {};

bobsGame.player  = function(which){
  this.which = which;
  this.rollDice = function () {
    diceVal = Math.floor(Math.random() * 6 + 1);
    console.log(diceVal);
    return diceVal;
  }
}

var player1 = new bobsGame.player('player1');

否则，您可以使用：

$('#roll-dice-btn-1').click(function(){
  player1.rollDice();
});

为什么我的javascript对象方法返回undefined？

6 个答案: