- Object.is(v1, v2)
- 判断2个数据是否完全相等
- Object.assign(target, source1, source2..)
- 将源对象的属性复制到目标对象上
- 直接操作 proto 属性
let obj2 = {};
obj2.proto = obj1;
console.log(0 == -0);//true
console.log(NaN == NaN);//false
console.log(Object.is(0, -0));//false
console.log(Object.is(NaN, NaN));//true
let obj3 = {};
let obj4 = {money: 5000000};
obj3.__proto__ = obj4;
console.log(obj3);//{}obj3为空
console.log(obj3.money);//5000000
