JavaScript 编号不会显示答案

【问题标题】：JavaScript Number Won't displayJavaScript 编号不会显示
【发布时间】：2020-03-19 16:40:13
【问题描述】：

我尝试用 JavaScript 制作一些 BlackJack 游戏，但我在显示当前玩家的分数时遇到了问题。

    let blackjackGame = {
    'you': {'scoreSpan': "#your-blackjack-result", 'div': '#your-box', 'score': 0},
    'dealer': {'scoreSpan': "#dealer-blackjack-result", 'div': '#dealer-box', 'score': 0},
    'cards': ['2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K', 'A'],
    'cardsMap': {'2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9, '10': 10, 'J': 10, 'Q': 10, 'K': 10, 'A': [1, 11]}
};

    function updateScore(card, activePlayer) {
    activePlayer['score'] += blackjackGame['cardsMap']['card'];
}

function showScore(activePlayer) {
    document.querySelector(activePlayer['scoreSpan']).textContent = activePlayer['score'];
}

HTML

<div  class="flex-box-blackjack-board">
                <div id="your-box">
                    <H2>You: <span id="your-blackjack-result">0</span></H2>
                </div>
                <div id="dealer-box">
                    <H2>Dealer: <span id="dealer-blackjack-result">0</span></H2>
                </div>
            </div>

当我点击按钮打牌时，分数显示 NAN 但如果我改变这一行：

    function updateScore(card, activePlayer) {
    activePlayer['score'] += blackjackGame['cardsMap']['card'];
}

通过这个：

    function updateScore(card, activePlayer) {
    activePlayer['score'] += blackjackGame['cardsMap']['k'];
}

分数显示 10 并且正常递增为什么我不能随机选择一张卡片并且分数显示好分数而不是 NaN？我没有看到任何错误。

感谢您的帮助

【问题讨论】：

标签： javascript random numbers show

【解决方案1】：

您的函数似乎有错误：

function updateScore(card, activePlayer) {
    activePlayer['score'] += blackjackGame['cardsMap']['card'];
    // above blackjackGame['cardsMap']['card'] returns undefined,
    // that's why you get NaN when you do a sum with number
}

你的意思不是像下面这样吗？

function updateScore(card, activePlayer) {
    activePlayer['score'] += blackjackGame['cardsMap'][card];
    // in this form we refer to the card argument passed to function
}

【讨论】：