ES6的对象扩展方法

一、Object.is 判断两个值是否完全相等

二、Object.assign 合并对象

三、Object.setPrototypeOf 设置原型对象

// Object.setPrototypeOf 设置原型对象
        const school = {
            name:'清华'
        }
        const cities = {
            city: ['北京','上海','广州']
        }
        Object.setPrototypeOf(school,cities)
        console.log(school)
        console.log(Object.getPrototypeOf(school))