<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    /*基础数据类型
        number string boolean undefined null symbol
      引用数据类型
      object
    */

    // 内置对象
    // console.dir(document);

    // let x = {
    //     name:'zy'
    // };
    // x.age = 18;
    // console.log(x);

    // let x = [999];
    // x['goudan'] = '狗蛋';
    // console.log(x);

    // document.goudan = 456;
    // console.dir(document)

    let x = {
        name:'zy',
        age:18
    };
    //x[Symbol('age')]=88;//这样是没有意义的必须放入变量中存，不然取不到

    let y = Symbol('age');
    x[y]=99;

    console.log(x);


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