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我正在开发一个简单的二十一点程序。我对 javascript 完全陌生，在调试我的程序时遇到了麻烦。我不断收到 TypeError: cannot call getNumber method of undefined ..... 而且我完全迷路了。我正在尝试获取为每张卡存储的数值，但似乎这就是我在类printHand()内的方法中发生的错误Hand。当打印出两张或多张牌的手牌时，我会遍历手牌中的每张牌，并调用每手牌的数组在cards[i].getNumber()哪里。cards[]我没有正确引用卡片 [] 吗？我仔细检查以确保我的方法和变量设置为公共，但我仍然无法弄清楚为什么getNumber()在未定义的对象上被调用。我引用这个对象的方式有问题吗？

这是我的代码：

 // Card Constructor
function Card (suit, number){
var the_suit = suit;
var the_number = number;

this.getNumber = function(){
    return the_number;
};
this.getSuit = function(){
    return the_suit;    
};
this.getValue = function (){
    // face cards
    if(the_number > 10){
        return 10;

    // aces
    } else if (the_number < 2){
        return 11;

    // other cards
    } else {
        return the_number;
    }   
};
}

function deal (){
// get card suit
var rand1 = Math.floor(Math.random ( ) * 4 + 1);
// get car number
var rand2 = Math.floor(Math.random ( ) * 13 + 1);

var newCard = new Card(rand1, rand2);
}

function Hand (){
// create two cards for initial hand
var card1 = deal();
var card2 = deal();
// store cards in array
var cards = [card1,card2];

// getter
this.getHand = function (){
    return cards;
};

// get the score
this.score = function(){
    var length = cards.length;
    var score = 0;
    var numAces = 0;

    for(i = 0; i < length; i++){
    if (cards[i].getValue() === 11 ){
    numAces++;
    }   
        score += cards[i].getValue();   
    }
    while(score > 21 && numAces !== 0){
        sum -= 10;
        numAces--;
    }
};
this.printHand = function(){
    var length = cards.length;

    for(i=0; i< length; i++){
    var string = string + cards[i].getNumber() + " of suit " + cards[i].getSuit() + ", ";
    }
    return string;
};

this.hitMe = function(){
    var newCard = deal();
    cards.push(newCard);

}
}

function playAsDealer(){
var newHand = new Hand();
while(newHand.score < 17){
    newHand.hitMe();
}
return newHand;
}

function playAsUser(){
var newHand = new Hand();
var choice = confirm("Current hand: "+ newHand.printHand() + ": Hold (Ok) or Stand(Cancel)");
while(choice){
    newHand.hitMe();
    choice = confirm("Current hand: "+ newHand.printHand() + ": Hold (Ok) or Stand(Cancel)");

}
}

function declareWinner(user, dealer){

//user wins case
if (user.score > dealer.score){
console.log("You are the Champion!");
}

// tie game
else if(user.score===dealer.score){
    console.log("Tied!");
}

else{
    console.log("Loser!!");
}

}


function playGame (){
var user = playAsUser();
var dealer = playAsDealer();
console.log("User's Hand: " + user.printHand());
console.log("Dealer's Hand: " + dealer.printHand());
declareWinner();
}


playGame();
4

2 回答 2

1

您不会在函数“deal”中返回卡片对象：应该是：

function deal (){
   // get card suit
 var rand1 = Math.floor(Math.random ( ) * 4 + 1);
        // get car number
 var rand2 = Math.floor(Math.random ( ) * 13 + 1);

 var newCard = new Card(rand1, rand2);

 return newCard;
}
于 2013-03-20T01:03:23.157 回答
1

有一些问题，但要让你开始：

我得到的错误是“TypeError：cards[i] is undefined”。既然你这样调用你的 deal() 函数：

var card1 = deal();

您需要在交易功能中退回卡，因此请更改

var newCard = new Card(rand1, rand2);

到

return new Card(rand1, rand2);

您还需要在打印手牌时将 :cards[i].getNumber() 转换为字符串

于 2013-03-20T01:05:51.603 回答