js defineProperty vs Proxy

最新推荐文章于 2025-03-11 11:22:32 发布

炉火纯青-旺

最新推荐文章于 2025-03-11 11:22:32 发布

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文章标签： javascript 前端

本文链接：https://blog.youkuaiyun.com/qq_34870529/article/details/123155181

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demo.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>defineProperty vs Proxy</title>
</head>
<body>
    <script type="module">
        /** defineProperty **/
        let obj = {
            name: '张三',
            age: 20
        };

        for(let key in obj){
            let value = obj[key];
            Object.defineProperty(obj, key, {
                configurable: true, 
                enumerable: true,
                get(){
                    console.log('get');
                    return value;
                },
                set(newValue){
                    console.log('set');
                    value = newValue;
                }
            })
        }

        obj.name = '李四';

        console.log(obj.name);

        /** Proxy **/

        let obj = {
            name : '张三'
        };

        let newObj = new Proxy(obj, {
            get(target, key){
                console.log('get');
                // return target[key];
                return Reflect.get(target, key);
            },
            set(target, key, newValue){
                console.log('set');
                // target[key] = newValue;
                // 严格模式下
                return Reflect.set(target, key, newValue);
            },
            // 判断key值是否存在于对象中
            has(target, key){
                console.log('has');
                return key in target;
            }

        });

        newObj[name];

        newObj.name = '李四';

        console.log('name' in newObj);

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