创建一个新的JSON数组，其中包含来自另一个JSON的特定属性

Question

I have this JSON array of objects

  "questions": [
  {
    "id": "id",
    "answer":"answer",
    "question_type": "q_type",
    "question": {
      "header":"Text",
      "question_image": "link", 
      "answers_list": ["array"],
    }
  },
  {
    "id": "id",
    "answer":"answer",
    "question_type": "q_type",
    "question": {
      "header": "Text",
      "question_image": "link",
      "choices_type": "text",
      "choices": ["array"] 
    }
  }
 ]

and i want to extract from this json another json that contain id and answer only like this

"answers": [{"question": question_id, "answer": "text"}]

Answer 1

You can use the JavaScript map function (assuming the variable q contains your questions object):

var out = q.questions.map(function(element) {
              return {"question": element.id, "answer": element.answer};
          });

Answer 2

Assuming both the question id and the answer are in the questions objects, then you could do it as follows:

var answers = [];

for(var i = 0; i < questions.length; i++)
{
    answers.push({
        question: questions[i].id,
        answer: questions[i].answer
    });
}

This also assumes you declare the questions array as var questions = ...

Answer 3

Here your json

var json = {"questions": [
  {
    "id": "id",
    "answe":"answer",
    "question_type": "q_type",
    "question": {
      "header":"Text",
      "question_image": "link", 
      "answers_list": ["array"]
    }
  },
  {
    "id": "id",
    "answer":"answer",
    "question_type": "q_type",
    "question": {
      "header": "Text",
      "question_image": "link",
      "choices_type": "text",
      "choices": ["array"] 
    }
  }
 ]}

Now iterate it and create a new Json object

var answers = []
var question = {}

json.questions.forEach(function(value, index){
    question.id = value.id;
    question.answer = value.answer;
    answers.push(question);

});

var resultJson = {};

resultJson.answers = answers;

Answer 4

var answers = questions.reduce(function (result, question){
    return result.concat(item.question.answers_list.map(function (answer) {
        return {
            question: {
                id: question.id
            },
            answer: answer
        }
    }));
}, []);

You'll need to 'map' question's data, because you'll need to be careful of circular references if you want to parse it to JSON. But you specify all you want is the question.id. So that's no problem.

Answer 5

This will map your original JSON to the specified JSON. Uses a reviver function.

 var json = '{"questions":[{"id":"id","answer":"answer","question_type":"q_type","question":{"header":"Text","question_image":"link","answers_list":["array"]}},{"id":"id","answer":"answer","question_type":"q_type","question":{"header":"Text","question_image":"link","choices_type":"text","choices":["array"]}}]}'; var keep = ['', 'questions', 'id', 'answer']; var newJson = JSON.stringify(JSON.parse(json, function(k, v) { var idx = k && k == +k; if (idx || keep.indexOf(k) > -1) { if (idx && typeof v === 'object') { var id = v.id; delete v.id; v.question = id; } return v; } })); document.body.textContent = newJson; console.log(newJson);