如何拦截 for ...in 操作

Question

可以使用 ownKeys

const obj = {
  name: 'Alice',
  age: 20,
  gender: 'female'
};

const handler = {
  ownKeys(target) {
    const keys = Reflect.ownKeys(target);
    return keys.filter(key => typeof key !== 'symbol');
  }
};

const proxyObj = new Proxy(obj, handler);

for (let key in proxyObj) {
  console.log(key);
}