隐藏属性

隐藏属性

• 代理的内部实现对外部代码是不可见的，因此要隐藏目标对象上的属性也轻而易举。比如

  const hiddenProperties = ["foo", "bar"];
  const targetObject = {
    foo: 1,
    bar: 2,
    baz: 3,
  };
  const proxy = new Proxy(targetObject, {
    get(target, property) {
      if (hiddenProperties.includes(property)) {
        return undefined;
      } else {
        return Reflect.get(...arguments);
      }
    },
    has(target, property) {
      if (hiddenProperties.includes(property)) {
        return false;
      } else {
        return Reflect.has(...arguments);
      }
    },
  });
  // get()
  console.log(proxy.foo); // undefined
  console.log(proxy.bar); // undefined
  console.log(proxy.baz); // 3
  
  // has()
  console.log("foo" in proxy); // false
  console.log("bar" in proxy); // false
  consolr.log("baz" in proxt); // true