javascript - 尝试使用数组和循环重写 JS 测验——正确答案在哪里？

Question

在了解什么是循环和数组之前，我写了一个小型 JS 测验，现在我正在尝试对其进行一些整理。最初的测验会在警报窗口中向用户提问，如果他们回答错误，它会告诉他们正确的答案是什么。如果答案正确，它会告诉他们他们是正确的，然后再继续下一个问题。它还会记录用户得到正确或错误答案的数量。这是我原来的(过多的)代码:

var correct = 0;

var answer1 = prompt("What is the capital of England?");
  if (answer1.toUpperCase() === "LONDON") {
    alert("That's correct!")
    correct += 1
  }
  else {
    alert("False. The correct answer is London.")
  }

var answer2 = prompt("What is the capital of France?")
   if (answer1.toUpperCase() === "PARIS") {
    alert("That's correct!")
    correct += 1
  }
  else {
    alert("False. The correct answer is Paris.");
  }

var answer3 = prompt("What is the capital of Canada?")
  if (answer3.toUpperCase() === "OTTAWA") {
    alert("That's correct!");
    correct += 1
  }
  else {
    alert("False. The correct answer is Ottawa.");
  }

document.write("<h1>You answered " + correct + " out of 5 questions correctly.</h1>")

if (correct === 5) {
  document.write("You won a gold star!");
}
  else if (correct >= 3) {
  document.write("You won a silver star.");
}

  else if (correct >= 2) {
  document.write ("You win third place.");
}

else {
  document.write("Sadly, you did not win any stars.");
}

正如你所看到的，这篇文章很长而且很新手。这是我一直在重写的内容:

var questions = [
["What is the capital of England?", "LONDON"]
["What is the capital of France?", "PARIS"]
["What is the capital of Canada?", "OTTAWA"]
]

var correctAnswers = 0; 

for (var i = 0; i < questions.length ; i += 1 ) {
question = questions[i][0];
answer = questions[i][1];
response = prompt(question);
response = toUpperCase(response);
if response === answer {
correctAnswers += 1;
}

我有点迷失的是正确答案的结构和位置，如果用户回答错误，这些正确答案会通过警报窗口中的测验向用户显示。我是否需要向二维数组添加第三列，然后在 for 循环中引用它，即 CorrectResponse = [i][2]？或者我应该采取完全不同的方式来解决这个问题？

Answer 1

你只是缺少了一些逗号，你的数组就搞乱了。您不再需要使数组的结构变得复杂。不过，各个数组项之间没有逗号。

本质上，您循环遍历整个数组，并为每个子项目打印问题的 questions[i][0] 和 questions[i][1] 的问题答案

var questions = [
["What is the capital of England?", "LONDON"],
["What is the capital of France?", "PARIS"],
["What is the capital of Canada?", "OTTAWA"]
];

var correctAnswers = 0;

for (var i = 0; i < questions.length; i++) {
    var answer = prompt(questions[i][0]);
    if (answer.toUpperCase() == questions[i][1]) {
        alert("Correct!");
        correctAnswers++;
    }
    else {
        alert("incorrect, the correct answer was " + questions[i][1]);
    }
}

如果问题正确，则提供自定义响应示例:您只需将另一个项目添加到每个问题数组中，并且仅在他们答对问题时才显示该项目。

var questions = [
["What is the capital of England?", "LONDON", "You know, where the queen lives"],
["What is the capital of France?", "PARIS", "Remember the eiffel tower?"],
["What is the capital of Canada?", "OTTAWA", "Lot of mooses there"]
];

var correctAnswers = 0;

for (var i = 0; i < questions.length; i++) {
    var answer = prompt(questions[i][0]);
    if (answer.toUpperCase() == questions[i][1]) {
        alert("Correct! " + questions[i][2]);
        correctAnswers++;
    }
    else {
        alert("incorrect, the correct answer was " + questions[i][1]);
    }
}