从给定数组创建一个新数组并获得不同的属性作为子对象/数组

Question

我有多个 id 但问题答案不同的 Responses 数组。

Responses = 
[0:{Id : 1,Name : John, QuestionId :1,Answer :8},
1:{Id : 1,Name : John, QuestionId :2,Answer :9},
2:{Id : 1,Name : John, QuestionId :3,Answer :3},
3:{Id : 1,Name : John, QuestionId :4,Answer :2},
4:{Id : 2,Name : Mark, QuestionId :1,Answer :6},
5:{Id : 2,Name : Mark, QuestionId :2,Answer :2},
6:{Id : 2,Name : Mark, QuestionId :3,Answer :5},
7:{Id : 2,Name : Mark, QuestionId :4,Answer :1}]
----------------------------------------------------------------
Output I want :
 
Arr = 
[0:{Id : 1,Name : John,
 Question : [{QuestionId :1,Answer :9},{QuestionId :2,Answer :8},{QuestionId :3,Answer :3},{QuestionId :4,Answer :2}]},
1:{Id : 2,Name : Mark,
 Question : [{QuestionId :1,Answer :6},{QuestionId :2,Answer :2},{QuestionId :3,Answer :5},{QuestionId :4,Answer :1}]}]
---------------------------------------------------------

我想创建一个包含 ID、名称和一个问题 object 的数组，其中包含问题 ID 和答案。 我尝试了不同的方式，但这对我不起作用。 如果你能在这里帮助我，那就太好了。 谢谢你。

Answer 1

您首先必须按Name对数据进行分组。 获得分组数据后，map 值。 映射时，您可以解构第一个问题的Id和Name字段，然后将QuestionId和Answer字段分解为Question字段。

 const groupBy = (arr, key) => arr.reduce((acc, item) => ({...acc, [item[key]]: [...(acc[[item[key]]]?? []), item ] }), {}); const responses = [ { "Id": 1, "Name": "John", "QuestionId": 1, "Answer": 8 }, { "Id": 1, "Name": "John", "QuestionId": 2, "Answer": 9 }, { "Id": 1, "Name": "John", "QuestionId": 3, "Answer": 3 }, { "Id": 1, "Name": "John", "QuestionId": 4, "Answer": 2 }, { "Id": 2, "Name": "Mark", "QuestionId": 1, "Answer": 6 }, { "Id": 2, "Name": "Mark", "QuestionId": 2, "Answer": 2 }, { "Id": 2, "Name": "Mark", "QuestionId": 3, "Answer": 5 }, { "Id": 2, "Name": "Mark", "QuestionId": 4, "Answer": 1 } ]; const arr = Object.values(groupBy(responses, 'Name')).map(questions => { const [ { Id, Name } ] = questions; return { Id, Name, Question: questions.map(({ QuestionId, Answer }) => ({ QuestionId, Answer })) }; }); console.log(arr);

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或者，您可以跳过分组而只是减少。 这有点耦合，但它切断了映射。

 const reduceBy = (arr, key) => Object.values(arr.reduce((acc, item) => { const { Id, Name, QuestionId, Answer } = item, prev = acc[[item[key]]] || { Id, Name, Question: [] }; return {...acc, [item[key]]: {...prev, Question: [...prev.Question, { QuestionId, Answer } ] } }; }, {})); const responses = [ { "Id": 1, "Name": "John", "QuestionId": 1, "Answer": 8 }, { "Id": 1, "Name": "John", "QuestionId": 2, "Answer": 9 }, { "Id": 1, "Name": "John", "QuestionId": 3, "Answer": 3 }, { "Id": 1, "Name": "John", "QuestionId": 4, "Answer": 2 }, { "Id": 2, "Name": "Mark", "QuestionId": 1, "Answer": 6 }, { "Id": 2, "Name": "Mark", "QuestionId": 2, "Answer": 2 }, { "Id": 2, "Name": "Mark", "QuestionId": 3, "Answer": 5 }, { "Id": 2, "Name": "Mark", "QuestionId": 4, "Answer": 1 } ]; const arr = reduceBy(responses, 'Name'); console.log(arr);

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Answer 2

const arr = [ 
  {Id : 1,Name : "John", QuestionId :1,Answer :8},
  {Id : 1,Name : "John", QuestionId :2,Answer :9},
  {Id : 1,Name : "John", QuestionId :3,Answer :3},
  {Id : 1,Name : "John", QuestionId :4,Answer :2},
  {Id : 2,Name : "Mark", QuestionId :1,Answer :6},
  {Id : 2,Name : "Mark", QuestionId :2,Answer :2},
  {Id : 2,Name : "Mark", QuestionId :3,Answer :5},
  {Id : 2,Name : "Mark", QuestionId :4,Answer :1}
]

let newObj = {};
arr.forEach(({ Id, Name, QuestionId, Answer }) => {
  if(newObj[Id]) {
    newObj[Id]["Question"] = [
      ...newObj[Id]["Question"],
      { QuestionId, Answer }
    ]
  } else {
    newObj[Id] = {
      Id,
      Name,
      Question: [{ QuestionId, Answer }]
    } 
  }
})

console.log(Object.values(newObj).flat()); 

Answer 3

const a = [{Id : 1,Name : 'John', QuestionId :1,Answer :8},
           {Id : 1,Name : 'John', QuestionId :2,Answer :9},
           {Id : 1,Name : 'John', QuestionId :3,Answer :3},
           {Id : 1,Name : 'John', QuestionId :4,Answer :2},
           {Id : 2,Name : 'Mark', QuestionId :1,Answer :6},
           {Id : 2,Name : 'Mark', QuestionId :2,Answer :2},
           {Id : 2,Name : 'Mark', QuestionId :3,Answer :5},
           {Id : 2,Name : 'Mark', QuestionId :4,Answer :1}]

const result = a.reduce((acc,curVal,index,src)=>{
    const {Id, Name, QuestionId,Answer} = curVal
    if(index===0 ){
        acc.push({Id,Name,Question:[{QuestionId, Answer}]})
    }else{
        const itemId = acc.findIndex(el=>el.Id===curVal.Id)
        if(itemId>= 0){
            acc[itemId].Question.push({QuestionId, Answer})
        }else{
            acc.push({Id,Name,Question:[{QuestionId, Answer}]})
        }
    }
  
    return acc
},[])

console.log(result)

Answer 4

您可以使用Set提取唯一名称，然后使用这些名称过滤Resopnses数组中的项目：

 let Responses=[{Id:1,Name:"John",QuestionId:1,Answer:8},{Id:1,Name:"John",QuestionId:2,Answer:9},{Id:1,Name:"John",QuestionId:3,Answer:3},{Id:1,Name:"John",QuestionId:4,Answer:2},{Id:2,Name:"Mark",QuestionId:1,Answer:6},{Id:2,Name:"Mark",QuestionId:2,Answer:2},{Id:2,Name:"Mark",QuestionId:3,Answer:5},{Id:2,Name:"Mark",QuestionId:4,Answer:1}]; let result = [...new Set(Responses.map(({Name}) => Name))].map(e => Responses.filter(({Name}) => Name === e)) console.log(result)