JavaScript循环在应该结束的时候没有结束

Question

我正在做一个21人的游戏(也称为21点)，我不确定为什么我的程序忽略了这个条件语句，如果用户的卡片值超过21，循环结束，有人能告诉我这里会有什么问题吗？谢谢。(这段代码还没有完成，所以请原谅我的混乱。)(另请参阅“下面的问题”的评论)

let cardRange = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var cardOne = cardRange[Math.floor(Math.random()*cardRange.length)];
var cardTwo = cardRange[Math.floor(Math.random()*cardRange.length)];
var cardTotal = cardOne + cardTwo;
var comScore = 18;
var i;
var extracard;


alert(`Your card numbers are ${cardOne} and ${cardTwo}!`);
//user gets to draw 5 cards in total
for(i = 0; i<3;){
var input = prompt(`Which makes your card total ${cardTotal}. Would you like to draw another card? (Type in 1 for yes, 0 for no, or select cancel to return to home.)`);


if (input === null){
    i+=3;
    window.location.replace("http://stackoverflow.com");
}
else if (input === "1"){
    i++;
    extraCard = cardRange[Math.floor(Math.random()*cardRange.length)];
    alert(`This card's number is ${extraCard}!`);
    cardTotal = extraCard + cardTotal;

}
else if (input === "0"){
    i+=3;
}
//problem below
else if (cardTotal >=22){
    i+=3;
}
//not working, loop will not end.
else{
alert("Lmao wrong input you rart");
}
}


function pontoonOutput(){
    if (cardTotal > comScore && cardTotal < 22){
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... You win!`);
    }
    else if (cardTotal === comScore){
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... It is a tie!`);
    }
    //this outputs if the user gets above 22
    else if (cardTotal >= 22){
        alert("BUST!");
        document.write(`Your card number is ${cardTotal}, which is above 21. Which means.... You lose!`);
    }
    //what should happen if line 29 is picked up. ^
    else{
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... You lose!`);
    }
    }
    
    pontoonOutput();

Answer 1

问题是它是else的一部分，所以只要他们输入1、0或null，它就永远不会命中。你可能只想在最后把它移到它自己的状态：

​

let cardRange = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var cardOne = cardRange[Math.floor(Math.random() * cardRange.length)];
var cardTwo = cardRange[Math.floor(Math.random() * cardRange.length)];
var cardTotal = cardOne + cardTwo;
var comScore = 18;
var i;
var extracard;


alert(`Your card numbers are ${cardOne} and ${cardTwo}!`);
//user gets to draw 5 cards in total
for (i = 0; i < 3;) {
    var input = prompt(`Which makes your card total ${cardTotal}. Would you like to draw another card? (Type in 1 for yes, 0 for no, or select cancel to return to home.)`);


    if (input === null) {
        i += 3;
        window.location.replace("http://stackoverflow.com");
    } else if (input === "1") {
        i++;
        extraCard = cardRange[Math.floor(Math.random() * cardRange.length)];
        alert(`This card's number is ${extraCard}!`);
        cardTotal = extraCard + cardTotal;

    } else if (input === "0") {
        i += 3;
    } else {
        alert("Lmao wrong input you rart");
    }
    //problem below
    if (cardTotal >= 22) {
        i += 3;
    }
    //not working, loop will not end.

}


function pontoonOutput() {
    if (cardTotal > comScore && cardTotal < 22) {
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... You win!`);
    } else if (cardTotal === comScore) {
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... It is a tie!`);
    }
    //this outputs if the user gets above 22
    else if (cardTotal >= 22) {
        alert("BUST!");
        document.write(`Your card number is ${cardTotal}, which is above 21. Which means.... You lose!`);
    }
    //what should happen if line 29 is picked up. ^
    else {
        document.write(`You got ${cardTotal}, and the AI player got ${comScore}. Which means.... You lose!`);
    }
}

pontoonOutput();

​

Answer 2

问题是，您在相同的if...else语句中检查卡片总数，但在检查"0“或"1”输入之后。因此，如果用户输入"0“或"1"，您的代码将处理这些条件，并且永远不会进行卡片总数检查。

有很多方法可以解决这个问题。一种解决方案是将卡总检查移到主if...else逻辑之后的单独if条件中。如下所示：

for(i = 0; i<3;){
  var input = prompt(`Which makes your card total ${cardTotal}. Would you like to draw another card? (Type in 1 for yes, 0 for no, or select cancel to return to home.)`);

  if (input === null){
    // ...
  }
  else if (input === "1"){
    // ...
  }
  else if (input === "0"){
    // ...
  }

  // Keep separate from the main if...else logic to ensure it always gets run.
  if (cardTotal >=22){
    i+=3;
  }
}

Answer 3

尝试使用break语句。试着这样做：

​

for(i = 0; i<3;){
  var input = prompt(`Which makes your card total ${cardTotal}. Would you like to draw another card? (Type in 1 for yes, 0 for no, or select cancel to return to home.)`);

  if (input === null){
    // ...
  }
  else if (input === "1"){
    // ...
  }
  else if (input === "0"){
    // ...
  }
  
  if (cardTotal >=22){
    //i += 3;
    break;
  }
}

​

现在我明白了，它需要拆分