Object.keys()返回键

1.处理对象，返回键

let person = {name:"张三",age:25,address:"深圳",getName:function(){}}
Object.keys(person) // ["name", "age", "address","getName"]

2.处理数组，返回字符串数组索引

let arr = [1,2,3,4,5,6]
Object.keys(arr) // ["0", "1", "2", "3", "4", "5"]

3.处理字符串，返回字符串数组索引

let str = "12345字符串"
Object.keys(str) // ["0", "1", "2", "3", "4", "5", "6", "7"]

Object.values()返回值

Object.entries（）返回键值对