1.Object.keys

　　Object.keys(obj),返回給定物件的所有可列舉屬性的鍵名或者索引值的陣列

　a.給定物件為物件,返回鍵名陣列

let person = {name:"張三",age:25,address:"廈門",getName:function(){}}

console.log(Object.keys(person))  // ['name', 'age', 'address', 'getName']

　b.給定物件為陣列,返回索引陣列

let arr = ['ww','wx','zhangsan','lisi','wangwu']

console.log(Object.keys(arr)) 
 
// ['0', '1', '2', '3', '4']

　c.給定物件為字串,返回索引陣列

let str = 'dsafhlsafhas'

console.log(Object.keys(str)) // ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11']

2.Object.values

　Object.values與Object.keys相對,返回的是鍵值

   a.給定物件為物件,返回鍵值陣列

let person = {name:"張三",age:25,address:"廈門",getName:function(){}}

console.log(Object.values(person)) 
 
// ['張三', 25, '廈門', ƒ]

c.給定物件為字串,返回索引陣列

let str = 'dsafhlsafhas'

console.log(Object.values(str)) // ['d', 's', 'a', 'f', 'h', 'l', 's', 'a', 'f', 'h', 'a', 's'] 可以用 str.split('')直接實現