Question

我想在JS中创建一个调查应用程序，主要有以下代码：

for(var questionNumber in questionsAndAnswers.allQuestions){
      for(var i in questionsAndAnswers.allQuestions[questionNumber]){
        console.log(questionsAndAnswers.allQuestions[questionNumber].question);
        console.log(questionsAndAnswers[questionNumber+1]);
    } 
}

这个代码在配置中：

const questionsAndAnswers = {
    "allQuestions": [
        { "question": "Write your first question here",
        },
        { "question": "Write your second question here",
        },
        { "question": "Write your third question here",
      }
     ],
    "answerOne": [
        "1.This is the first answer",
        "1.This is the second answer",
        "1.This is the third answer"
        ],
    "answerTwo": [
        "2.This is the first answer",
        "2.This is the second answer",
        "2.This is the third answer"
      ],
     "answerThree": [
        "3.This is the first answer",
        "3.This is the second answer",
        "3.This is the third answer"
      ]
}

然后出现了：

Write your first question here
undefined
Write your second question here
undefined
Write your third question here
undefined

我想这样做：当提出第一个问题时，只会出现第一个答案，但是当我打电话console.log(questionsAndAnswers[questionNumber+1]);时会出现未定义。我尝试了很多选项，但主要问题是在更改config时，在不更改main的情况下将问题与答案分开并在动态上添加问题+答案。如果你能帮助我，我会非常感激。

谢谢！

Answer 1

questionNumber是表示索引的整数。因此，对于第一项questionNumber === 0，您正试图从questionsAndAnswers[0 + 1] === questionsAndAnswers[1]获得答案。由于您的对象上没有属性“1”，因此未定义。

如果你想使用与此类似的数据结构，我会建议：

for(var questionNumber in questionsAndAnswers.allQuestions){
  console.log(questionsAndAnswers.allQuestions[questionNumber].question);
  for(var i in questionsAndAnswers.allAnswers[questionNumber]){
    console.log(questionsAndAnswers[questionNumber][i]);
  } 
}

const questionsAndAnswers = {
  "allQuestions": [
    { "question": "Write your first question here" },
    { "question": "Write your second question here" },
    { "question": "Write your third question here" }
  ],
  "allAnswers": [
    [
      "1.This is the first answer",
      "1.This is the second answer",
      "1.This is the third answer"
    ],
    [
      "2.This is the first answer",
      "2.This is the second answer",
      "2.This is the third answer"
    ],
    [
      "3.This is the first answer",
      "3.This is the second answer",
      "3.This is the third answer"
    ]
  ]
}

但是，我鼓励您探索组织数据结构的不同方法，因为这种方式似乎有点奇怪。也许尝试为问题和答案创建单独的对象，或者在问题下嵌套答案。

Answer 2

我认为您应该重新考虑您的数据模型。您的questionsAndAnswers是一个对象，这意味着您不是通过整数来访问问题，而是通过键（“answerOne”，“answerTwo”，......）来访问。因此questionsAndAnswers[questionNumber+1]无效。它必须类似于questionsAndAnswers["answerOne"]。

但是我建议你将答案保存在问题对象中。

{
    "question": "Write your first question here",
    "answers": [...]
}

Answer 3

我使用了Tushar所说的内容：

我建议存储问题＆amp;同一个对象的答案。 { 题： “abc”，答案：[“abc”，“def”，ghi“]，正确：0}。

由于

从数组JavaScript中的数组调用带索引的数组元素

3 个答案: