SOURCE

let obj = {a:1,b:2,c:3}
console.log(delete obj.b);//true
console.log(Object.keys(obj))
console.log(Object.values(obj))
console.log(obj.hasOwnProperty('a'))
console.log('a' in obj)
for(key in obj){
    console.log(key)
}
// 对象合并,以assign的第一个参数为主,第二个对象中的属性值覆盖第一个参数
let objOne = {c:4, d:5}
Object.assign(obj,objOne)
console.log(obj)
// entrise,返回二维数组,配合,for of 解构赋值遍历
console.log(Object.entries(obj))
for(let [key,value] of Object.entries(obj)){
    console.log(key,value)
}