ES6 对象都新增了哪些属性

let name = "Ken"
let age = 18
let obj = {name, age}

let person = {
  sayHi() {
    console.log("halou")
  }
}

let person = {
  ['say'+'Hi']() {
    console.log("sayHi")
  }
}

const hello = "Hello"
const obj = {
 [hello+"2"]:"world"
}

let obj = {name: '人生代码', age: 18}

let someone = {...obj}

let one = {name: '人生代码'}
let two = {age: 18}

let someone = {...one, ...two}

let target = {name: "人生代码"}
let obj1 = {age: 18}
let obj2 = {sex: '男'}

Object.assign(target, obj1, obj2)

// target: {name: '人生代码', age: 18, sex: '男'}

Object.assign(null);       // TypeError: Cannot convert undefined or null to object
Object.assign(undefined);  // TypeError: Cannot convert undefined or null to object
当参数不止一个时，null 和 undefined 不放第一个，即不为目标对象时，会跳过 null 和 undefined ，不报错
Object.assign(1,undefined);  // Number {1}
Object.assign({a: 1},null);  // {a: 1}
 
Object.assign(undefined,{a: 1});  // TypeError: Cannot convert undefined or null to object

let sourceObj = { a: { b: 1}};
let targetObj = {c: 3};
Object.assign(targetObj, sourceObj);
targetObj.a.b = 2;
sourceObj.a.b;  // 2

targetObj = { a: { b: 1, c:2}};
sourceObj = { a: { b: "hh"}};
Object.assign(targetObj, sourceObj);
targetObj;  // {a: {b: "hh"}}

Object.assign([2,3], [5]);  // [5,3]

Object.is("q","q");      // true
Object.is(1,1);          // true
Object.is([1],[1]);      // false
Object.is({q:1},{q:1});  // false

//一是+0不等于-0
Object.is(+0,-0);  //false
+0 === -0  //true
//二是NaN等于本身
Object.is(NaN,NaN); //true
NaN === NaN  //false