Reflect的作用，target,property,value,receiver代表啥

每天吃饭的羊2023-11-18 16:28

1.真的proxy

let target ={name:'张三'}
let handler = {
  get(target,property,receiver){
    console.log(1,target,2,property,3,receiver)
    return Reflect.get(target,property,receiver)
  },
  set(target,property,value,receiver){
    console.log('a',target,'b',property,'c',value,'d',receiver)
    return Reflect.set(target,property,value,receiver)
  }
}
let proxy = new Proxy(target,handler)
console.log(proxy.name)
proxy.name = '李四'
// console.log(proxy.name)

以上代码用浏览器控制台运行下如下

可知target,property,value,receiver的值

不知道为啥这里的target换成多层的对象就不起作用了

let target ={name:'张三',info:{age:18,sex:'男'}}
console.log(proxy.info.sex)
proxy.info.sex = '女'

2.自己写的proxy

很明显这里的reflect.get被return target[key]替代，

reflect.set被 '=' 替代

说明了reflect在proxy的作用

let handler = {
  get(target, key, receiver) {
    console.log(1, target, 2, key, 3, receiver)
    return target[key];
  },
  set(target, key, value, receiver) {
    console.log('a', target, 'b', key, 'c', value, 'd', receiver)
    target[key] = value;
    return true;
  },
};
let target ={name:'张三'}
let proxy = new Proxy(target, handler);
console.log(proxy.name)
proxy.name = '李四'
console.log(proxy.name)