6.js

const idol = {
  name: 'Tom',
  phone: 10086,
  price: 1000000
}

const agent = new Proxy(idol, {
  get: function(target) {
    return 'phone:10010';
  },
  set: function(target, key, value) {
    if(key === 'price' ) {
      if(value < target.price) throw new Error('low price');
      target.price = value;
    }
  }
})


agent.phone;
agent.price = 100;