javascript - 数组结构转为对象?

Question

let arr =[{num:'2', text: 'aaa', quantity: 1},{num: '1', text: 'bbb', quantity: 2},{num: '2', text: 'ccc', quantity: 1},{num: '2', text: 'ddd', quantity: 1},{num: '1', text: 'eee', quantity: 1}]

转为

let obj ={1:[{answer:'bbb',quantity:2},{answer:'eee',quantity:1}],2:[{answer:'aaa',quantity:1},{answer:'ccc',quantity:1},{answer:'ddd',quantity:1}]}

用num作为key

Answer 1

非面试的话建议使用lodash

import _ from 'lodash';const arr = [  { num: '2', text: 'aaa', quantity: 1 },  { num: '1', text: 'bbb', quantity: 2 },  { num: '2', text: 'ccc', quantity: 3 },  { num: '2', text: 'ddd', quantity: 1 },  { num: '1', text: 'eee', quantity: 3 },  { num: '1', text: 'eee', quantity: 2 },];const res = _.groupBy(arr, 'quantity');

Answer 2

let arr = [  { num: "2", text: "aaa", quantity: 1 },  { num: "1", text: "bbb", quantity: 2 },  { num: "2", text: "ccc", quantity: 1 },  { num: "2", text: "ddd", quantity: 1 },  { num: "1", text: "eee", quantity: 1 },];const arr2Obj = (array) => {  let result = {};  array.forEach(({num, text, quantity})=>{    if(result[num] === undefined){      result[num] = []    }    result[num] = [...result[num], { text, quantity }];  })  return result;};const result = arr2Obj(arr);console.log(result);

Answer 3

const result = {};for (const item of data) {  const { num, text, quantity } = item;    if (result[num]) {    result[num].push({ answer: text, quantity });  } else {    result[num] = [{ answer: text, quantity }];  }}

Answer 4

let obj = {};arr.forEach(item => {    let { num, text, quantity } = item;    if (!obj[num]) {        obj[num] = [];    }    obj[num].push({ answer: text, quantity });});

Answer 5

let arr = [  { num: '2', text: 'aaa', quantity: 1 },  { num: '1', text: 'bbb', quantity: 2 },  { num: '2', text: 'ccc', quantity: 1 },  { num: '2', text: 'ddd', quantity: 1 },  { num: '1', text: 'eee', quantity: 1 }];let obj = {};// 遍历数组并将条目按照num属性值分组arr.forEach(item => {  const num = item.num;  const answer = item.text;  const quantity = item.quantity;    if (!obj[num]) {    obj[num] = [];  }    obj[num].push({ answer, quantity });});// 输出结果console.log(obj);