Question

我正在练习事件听众和功能，并且正在尝试构建一个非常简单的纸牌游戏。单击相应的按钮后，我的前2个函数可以获取卡1和2的值。我已经构建了第三个来组合总数，但是无法将生成的值拉到第三个函数中。我的第三个函数总是返回零。我明白了，但是还没有找到解决方案从前两个函数中提取值。感谢任何帮助。谢谢。

var cardButton = document.getElementById('cardButton1');
  var cardButton2 = document.getElementById('cardButton2');
  var cardValue = document.getElementById('cardValue');
  var cardValue2 = document.getElementById('cardValue2');
  var cardTotalButton = document.getElementById('cardTotalButton');
  var cardTotal = document.getElementById('displayTotal');
  var card1Value = 0;
  var card2Value = 0;
  var totalCardsValue = 0;
  var cardMin = 1;
  var cardMax = 14;


  function generateCard(){
    var card1Value = randCard();
    cardValue.innerHTML = 'card value is ' + card1Value;
    return card1Value;
  }

  function generateCard2(){
    var card2Value = randCard();
    cardValue2.innerHTML = 'card value is ' + card2Value;
    return card2Value;
  }

  function getPlayerTotal(){
    var totalCardsValue = card1Value + card2Value;
    //console.log(cardValue2 + 'test');
    cardTotal.innerHTML = 'card total is ' + totalCardsValue;

  }

cardButton.addEventListener('click',generateCard);
cardButton2.addEventListener('click',generateCard2);
cardTotalButton.addEventListener('click',getPlayerTotal);



function randCard(){
  var genRandCard = Math.floor(Math.random()*cardMax)+1;
  return genRandCard;
}

Answer 1

您正在将card1Value，card2Value和totalCardsValue重新声明为本地范围。移除前面的var。这样做，您不需要从generateCard()和generateCard()函数返回任何值，因为您正在使用全局变量。

  function generateCard(){
    card1Value = randCard(); //<-------Don't use var here
    cardValue.innerHTML = 'card value is ' + card1Value;
    return card1Value; //<-------This line is not really needed
  }

  function generateCard2(){
    card2Value = randCard(); //<-------Don't use var here
    cardValue2.innerHTML = 'card value is ' + card2Value;
    return card2Value; //<-------This line is not really needed
  }

  function getPlayerTotal(){
    totalCardsValue = card1Value + card2Value;  //<-------Don't use var here
    //console.log(cardValue2 + 'test');
    cardTotal.innerHTML = 'card total is ' + totalCardsValue;
  }

javascript从多个函数中提取值

1 个答案: