对象方法扩展

作用

• 对象的扩展运算符…将参数对象中的所有可遍历属性，拷贝到当前对象中

特点

• object.is ：判断两个值是否完全相等

console.log(Object.is(100, 100)); // true
console.log(Object.is(NaN, NaN)); // true
console.log(NaN === NaN); // false

• object.assign：对象的合并

const obj1 = { name: '2', age: 3 };
const obj2 = { gender: '男', age: 30 };
console.log(Object.assign(obj1, obj2)); // {name: '2', age: 30, gender: '男'}

• object.setPrototypeof、object.getPrototypeof：设置/获取原型对象

const school = {
    name: '河南大学',
};

const citys = {
    xiaoqu: ['郑州', '开封'],
};

Object.setPrototypeOf(school, citys);
console.log(school);
console.log(Object.getPrototypeOf(school));