javaScript数组和对象相互转换

ゞ浴缸里的玫瑰 2023-10-06 23:02 49阅读 0赞

#### 阅读目录 ####

*  一、数组转对象
 *   *  1.1、forEach
     *  1.2、reduce
 *  二、对象转数组
 *   *  1、for...in
     *  2、map

## 一、数组转对象 ##

[{
         id: 1, name: '张三' },{
         id: 2, name: '李四' }]
    转换为
    {
        1:'张三 ', 2:'李四'}

### 1.1、forEach ###

let arr = [{
         id: 1, name: '张三' },{
         id: 2, name: '李四' }]
    let obj = {
        }
    arr.forEach(item => obj[item.value] = item.name)
    
    console.dir(obj)
    /*
        Object
        1: "张三"
        2: "李四"
    */

### 1.2、reduce ###

let arr = [{
         id: 1, name: '张三' },{
         id: 2, name: '李四' }]
    let obj = arr.reduce((obj, item) => ({
        ...obj,[item.id]: item.name}), {
        })
    
    console.dir(obj)
    /*
        Object
        1: "张三"
        2: "李四"
    */

## 二、对象转数组 ##

{
        1:'张三', 2:'李四'}
    
     转换为
    
    [{
         id: 1, name: '张三' },{
         id: 2, name: '李四' }]

### 1、for…in ###

let obj = {
        1:'张三', 2:'李四'}
    let arr = []
    for (let index in obj) {
        
        arr.push({
        
            'id': index,
            'name': obj[index]
        })
    }
    
    console.dir(arr)
    /*
        Array(2)
        0: {id: '1', name: '张三'}
        1: {id: '2', name: '李四'}
        length: 2
    */

### 2、map ###

let obj = {
        1:'张三', 2:'李四'}
    let arr = Object.keys(obj).map(index => ({
         id: index, name: obj[index]}))
    
    console.dir(arr)
    /*
        Array(2)
        0: {id: '1', name: '张三'}
        1: {id: '2', name: '李四'}
        length: 2
    */