proxy

Proxy：

• 用法new Proxy(obj, handler)
• Proxy 中接受的 Receiver 形参表示代理对象本身或者继承与代理对象的对象

Reflect：

• Reflect.get(target, key, receiver)等价target[key].call(receiver)保证上下文this指向正确
• Reflect 中传递的 Receiver 实参表示修改执行原始操作时的 this 指向。

proxy代理对象

var obj = {
    a: 1,
    b: 2
};
var proxy = new Proxy(obj, {
    get: function(target, key, receiver) {
        return Reflect.get(target, key, receiver);
    },
    set: function(target, key, value, receiver) {
        return Reflect.set(target, key, value, receiver);
    }
});
//打印出来 proxy对象
/*
{
  deleteProperty: ƒ deleteProperty(target, key),
  get: ƒ (target, key, receiver),
  has: ƒ has(target, key),
  ownKeys: ƒ ownKeys(target),
  set: ƒ (target, key, value, receiver),
  a: 1,
  b: 2,
  ...
}
*/

proxy代理数组

var arr = [1,2,3]
var proxy = new Proxy(arr, {    
    get: function (target, key, receiver) {
         return Reflect.get(target, key, receiver);
     },
     set(target, key, value, receiver){
         return Reflect.set(target, key, value, receiver);
     }
 })
//打印出来 proxy对象
/*
{
  0: 1,
  1: 2,
  2: 3,
  deleteProperty: ƒ deleteProperty(target, key),
  get: ƒ (target, key, receiver),
  has: ƒ has(target, key),
  ownKeys: ƒ ownKeys(target),
  set: ƒ (target, key, value, receiver),
  ...
}
*/