对象解构2：嵌套解构 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>对象解构2：嵌套解构</title>
</head>
<body>

<script>
    let person = {
        name:'gpl',
        age:33,
        job:{
            title:'free'
        }
    };

    let person2 = {};
    ({name:person2.name,age:person2.age,job:person2.job} = person);

    //对象的引用被赋值，所以两者的改动都会影响到对方
    console.log(person2.job.title); //free
    person.job.title = 'richman';
    console.log(person2.job.title); //richman
    person2.job.title = 'god';
    console.log(person.job.title); //god


    //嵌套解构
    let {job:{title}} = person;
    console.log(title);

    //属性未定义的情况下不能使用嵌套解构

    let person3 = {
        name:'test'
    };
    //源对象上属性未定义
    // //报错：Cannot read properties of undefined (reading 'bar')
    // ({
    //     foo:{
    //         bar:person3.name
    //     }
    // }=person);

    //目标对象上属性未定义
    // //报错：Cannot set properties of undefined (setting 'title')
    // ({
    //     job:{
    //         title:person3.job.title
    //     }
    // } = person);





</script>
</body>
</html>

 

posted @ 2023-02-19 12:38  GPL-技术沉思录  阅读(19)  评论(0)  编辑  收藏  举报