ES6新特性——对象方法扩展

1.Object.is 判断两个值是否完全相等

<script>
    console.log(Object.is(120,120));    // true;
    console.log(Object.is(NaN,NaN));    // true;
    console.log(NaN === NaN);           // false;
</script>

2.Object.assign 对象的合并

<script>
    const config1 = {
        host: 'localhost',
        port: 3306,
        name: 'root',
        pass: 'root',
        text: 'text'
    }
    
    const config2 = {
        host: 'http://xxx.com',
        port: 33060,
        name: 'xxx.com',
        pass: 'zzz',
        xxx: '123'
    }
    
    console.log(Object.assign(config1,config2));    // config1 config2 中得重复项会被 config2 覆盖掉 ,不重复得会被保留, config2 中得不重复项也会被保留 
</script>

3.Object.setPrototypeOf　设置原型对象  Object.getPrototypeOf  获取原型对象

<script>
    const school = {
        name: 'xxx',
    }
    const cities = {
        xiaoqu: ['北京','上海','深圳']
    }
    Object.setPrototypeOf(school,cities);
　　 console.log(Object.getPrototypeOf(school));　　// 打印出cities对象
    console.log(school);                        // 在school原型对象中添加 cities 对象
</script>