Question

好的，所以我认为我这样做是对的，但显然出现了问题，因为我的代码永远存在。请记住我在高中和新编码所以可能有一个非常简单的解决方案，但我无法解决。

我有一个数据文件，其中包含各种问题数据。我的目标是从数据中随机选择一个问题，然后根据id的数组检查问题的ID。如果id出现在该数组中，我想重新运行随机选择功能来选择另一个问题。我想继续这样做，直到我有一个尚未出现的问题。

var dataFile = { 
'01': { questionID: '00100A', text: 'Random question number one?'},
'02': { questionID: '00200B', text: 'Random question number two?'},
'03': { questionID: '00300C', text: 'Random question number three?'},
'04': { questionID: '00400D', text: 'Random question number four?'},
'05': { questionID: '00500E', text: 'Random question number five?'},
'06': { questionID: '00600F', text: 'Random question number six?'},
'07': { questionID: '00700G', text: 'Random question number seven?'},
'08': { questionID: '00800H', text: 'Random question number eight?'},
'09': { questionID: '00900I', text: 'Random question number nine?'},
'10': { questionID: '01000J', text: 'Random question number ten?'}};

var questionsAsked = ['00100A', '00300C', '00500E', '00700G', '00900I'];

const keys = Object.keys(dataFile).map(key => dataFile[key]);

let selectedQuestion = keys[Math.floor(Math.random() * keys.length)];

let questionID = (selectedQuestion.questionID)

if (questionsAsked.includes(questionID)) {
  let selectedQuestion = keys[Math.floor(Math.random() * keys.length)];
  return selectedQuestion;
} else {
  questionsAsked.push(questionID);
  return selectedQuestion;
}

数据文件中有9个数据。还有一系列问题已被提出。我首先映射dataFile以获取问题数据，然后从中选择一个随机问题。我从该问题中提取questionID，然后使用if ... else语句来检查questionID是否出现在questionsAsked数组中。如果是这样，我重新选择另一个问题。如果没有，则将id推入数组并返回问题。

我的问题是，如果if语句为true，则选择另一个问题但从未再次检查以查看它是否出现在questionsAsked数组中。还尝试了一个while循环，看看是否有任何区别，但那是当我的代码陷入无限循环时。

while (questionsAsked.includes(guID)) {
  let selectedQuestion = keys[Math.floor(Math.random() * keys.length)];
  let questionID = (selectedQuestion.questionID);
}

questionsAsked.push(guID);
return selectedQuestion;

任何建议都非常适合

Answer 1

看看这个解决方案：

var dataFile = { 
'01': { questionID: '00100A', text: 'Random question number one?'},
'02': { questionID: '00200B', text: 'Random question number two?'},
'03': { questionID: '00300C', text: 'Random question number three?'},
'04': { questionID: '00400D', text: 'Random question number four?'},
'05': { questionID: '00500E', text: 'Random question number five?'},
'06': { questionID: '00600F', text: 'Random question number six?'},
'07': { questionID: '00700G', text: 'Random question number seven?'},
'08': { questionID: '00800H', text: 'Random question number eight?'},
'09': { questionID: '00900I', text: 'Random question number nine?'},
'10': { questionID: '01000J', text: 'Random question number ten?'}};

var questionsAsked = ['00100A', '00300C', '00500E', '00700G', '00900I'];

const keys = Object.keys(dataFile).map(key => dataFile[key]);

//wrapped it in a function
function randomQuestion()
{
  let selectedQuestion = keys[Math.floor(Math.random() * keys.length)];

  let questionID = (selectedQuestion.questionID)

  //if the question does not exists in the array indexOf will return -1
  //so push the answer into the array and return selected
  if (questionsAsked.indexOf(questionID) === -1) {
    questionsAsked.push(questionID);
    return selectedQuestion;
  } else {
   //if it does exist make it recursive and run again until it does.
   if (questionsAsked.length < keys.length)
     {
      return randomQuestion();
     }
   else {
    return {"message" : "There are no more random questions."};
   }
  }
}

document.querySelector("button").addEventListener("click", function(){
  console.log(randomQuestion(), questionsAsked);
});

<button>role it</button>

如何检查项目是否出现在数组中并重新选择新的内容？

1 个答案: