1.删属性

delete obj.xxx 或者 delete obj['xxx']

let obj = {name:'八戒',age:25}
delete obj.name //{age:25}
delete obj['age'] //{}

2.读属性（查）

• Object.keys(xxx)
• Object.value(xxx)
• Object.entries(xxx)
• console.dir(xxx) =>(查看xxx对象的所有属性名、值，包括隐藏属性)

let obj2 = {name:'悟空',age:24}
Object.keys(obj2) //查看对象属性名=> ['name','age']
Object.values(obj2)//查看对象属性值 =>['悟空',24]
Object.entries(obj2)//查看对象属性名和属性值 => ['name','悟空'] ['age',24]
obj2['age'] //24
obj2.age //24

3.修改或增加属性（写）

let obj3 = {name:'嘎子',age:33}
obj3.name = '小胖墩' //改 {name:'小胖墩'，age:33}
obj3.gender = '男' //增 {name: '小胖墩', age: 33, gender: '男'}
Object.assign(obj3,{a:1,b:'b'}) //批量修改（赋值） {name: '小胖墩', age: 33, gender: '男', a: 1, b: 'b'}