javascript从新对象中的键值对的两个级别的数组中提取ID

Question

I'm getting a payload back that I need to pull id's from two separate levels within the payload and return it as a single object of key value pairs. I was attempting to do some sort of combination or ForEach() and reduce() but I couldn't seem to find the right way of doing it. Here is a what the data looks like.

{
 orderId:999,
 menuId: 123456,
  questions:[{
    questionId: 123,
    depth: 1,
        answers: [
            { answerId: 999, text: "foo1" },
            { answerId: 888, text: "foo2" }]
  },
  {
    questionId: 654,
    depth: 1,
    answers: [{ answerId: 777, text: "bar" }]
  }]
}

What I'm attempting to have as the result

{"q_123": ["999", "888"], "q_654": "777"}

Answer 1

The following approach with reduce will do the job:

 const data = { orderId: 999, menuId: 123456, questions: [{ questionId: 123, depth: 1, answers: [{ answerId: 999, text: "foo1" }, { answerId: 888, text: "foo2" } ] }, { questionId: 654, depth: 1, answers: [{ answerId: 777, text: "bar" }] } ]}; const result = data.questions.reduce((all, { questionId: id, answers }) => { all[`q_${id}`] = answers.map(a => a.answerId); return all; }, {}); console.log(result); 

Answer 2

you can use reduce to achieve this :

 const data = { orderId: 999, menuId: 123456, questions: [ { questionId: 123, depth: 1, answers: [ { answerId: 999, text: "foo1"}, { answerId: 888, text: "foo2"} ] }, { questionId: 654, depth: 1, answers: [ { answerId: 777, text: "bar" }] } ] } const result = data.questions.reduce((acc, {questionId, answers}) => { return Object.assign({ [`q_${questionId}`]: answers.map( ({answerId}) => answerId ) }, acc) }, {}); console.log(result) 

Answer 3

This is with simple JSON parsing .

 var input = { orderId:999, menuId: 123456, questions:[{ questionId: 123, depth: 1, answers: [ { answerId: 999, text: "foo1" }, { answerId: 888, text: "foo2" }] }, { questionId: 654, depth: 1, answers: [{ answerId: 777, text: "bar" }] }] }; var length = input.questions.length; var questionsobj = input.questions; var resultJsonData = {}; for(var i=0; i<length; i++) { var question_id = questionsobj[i].questionId; var answersobj = questionsobj[i].answers; var len = answersobj.length; var arrayObject = []; for(var k=0; k<len; k++) { arrayObject[k] = answersobj[k].answerId; } resultJsonData["q_" + question_id] = arrayObject; } console.log(JSON.stringify(resultJsonData));