Object.keys()、Object.values()、Object.entries()的详细用法案例。

墨蓝 2022-11-20 08:18 195阅读 0赞

## 一、object.keys() ##

**1、`object.keys()`传入对象，返回一个数组类型 `值是方法中对象的键（key）`**

let obj={name:"小白",age:18,sex:"男"}
    let newobj=Object.keys(obj)
    console.log(newobj)//["name", "age", "sex"]
     newobj.map(item=>{
    console.log("键名为"+"："+item+"----"+"键值为"+"："+obj[item])
    })

控制台打印结果  
![在这里插入图片描述][20201027174845406.png_pic_center]**2、传入字符串返回索引**

let obj="ABCD123"
    let newobj=Object.keys(obj)
    console.log(newobj)//["0", "1", "2", "3", "4", "5", "6"]
    console.log(obj[2])//C

**3、传放入数组返回索引**

let obj=["a","b","c","d"]
    let newobj=Object.keys(obj)
    console.log(newobj)//["0", "1", "2", "3"]
    console.log(obj[1])//b

## 二、Object.values() ##

**1、`Object.values()`传入对象,返回一个数组类型 `值是方法中对象的值（value）`**

let obj={name:"小白",age:18,sex:"男"}
    let newobj=Object.values(obj)
    console.log(newobj)//["小白", 18, "男"]

**2、`Object.values()`传入对象，返回对象顺序成员**

let arr={5:"a",4:"b",3:"c",2:"d",1:"e"}
    console.log(Object.values(arr))//["e", "d", "c", "b", "a"]

## 三、Object.entries() ##

1、`Object.entries()`传入对象，返回一个数组类型 值是方法中对象的键和值

let obj={name:"小白",age:18,sex:"男"}
    let newobj=Object.entries(obj)
    console.log(newobj)//[["name", "小白"],["age", 18],["sex", "男"]]

控制台打印结果:  
![在这里插入图片描述][20201027175505857.png_pic_center]  
**2、`Object.entries()`传入数组，返回数组包数组的形式**

let obj=["a","b","c","d"]
    let newobj=Object.entries(obj)
    console.log(newobj)//[["0", "a"],["0", "b"],["0", "c"],["0", "d"]]

[20201027174845406.png_pic_center]: /images/20221120/b9ee2c032d914d509c114b31fe986244.png
[20201027175505857.png_pic_center]: /images/20221120/fa83686c033e4e41b48fd0f9f05df141.png