proxy是es6里面標(biāo)準(zhǔn)化構(gòu)造對象攔截器的類
使用方法

new Proxy(target, handler)

基本用法

let data = { 
  name: 'jack',
  age: 20
}
let handler = {
  get: function(target, key, proxy){
    const today = new Date(); 
    console.log(`GET request made for ${key} at ${today}`); 
    return Reflect.get(target, key, proxy);
  }
}
let p = new Proxy(p, handler)
console.log(p.name)

操作轉(zhuǎn)發(fā)

let target = {}
let p = new Proxy({}, target)
p.a = 12
console.log(target.a) // 12