javaScript数组和对象相互转换

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
*/