Reflect对象的方法与Proxy对象的方法一一对应，只要是Proxy对象的方法，就能在Reflect对象上找到对应的方法。Reflect对象一共有 13 个静态方法，可以理解为统一的对象操作API：

Reflect.apply(target, thisArg, args)
Reflect.construct(target, args)
Reflect.get(target, name, receiver)
Reflect.set(target, name, value, receiver)
Reflect.defineProperty(target, name, desc)
Reflect.deleteProperty(target, name)
Reflect.has(target, name)
Reflect.ownKeys(target)
Reflect.isExtensible(target)
Reflect.preventExtensions(target)
Reflect.getOwnPropertyDescriptor(target, name)
Reflect.getPrototypeOf(target)
Reflect.setPrototypeOf(target, prototype)

上面这些方法的作用，大部分与Object对象的同名方法的作用都是相同的。

proxy构造函数中的方法：

const obj = {
  name: 'zs',
  age: 18
};
const objProxy = new Proxy(obj, {
  get(target, property) {
    console.log(target, property);   // { name: 'zs', age: 18 } name     { name: 'zs', age: 18 } a
    return property in target ? target[property] : 'defaultValue';
  },
  set(target, property, value) {
    console.log(target, property, value);  // { name: 'zs', age: 18 } sex man       { name: 'zs', age: 18, sex: 'man' } age 12
    if (property === 'age') {
      if (!Number.isInteger(value)) {
        throw new TypeError(`${value} is not an int`);
      }
    }
    target[property] = value;
  }
});
console.log(objProxy.name);  // zs
console.log(objProxy.a);  //  defaultValue
objProxy.sex = 'man';
console.log(objProxy);  // { name: 'zs', age: 18, sex: 'man' }
objProxy.age = '12';  
/** throw new TypeError(`${value} is not an int`);
        ^
TypeError: 12 is not an int */ 

reflect静态方法：

const obj = {
  name: 'zs',
  age: 18
};
const objProxy = new Proxy(obj, {
  get(target, property) {
    return Reflect.get(target, property);
  }
});
console.log(objProxy.name);  // zs


const obj = {
  name: 'zs',
  age: 18
};
// console.log('age' in obj);
// console.log(delete obj['name']);
// console.log(Object.keys(obj));
console.log(Reflect.has(obj, 'age'));  // true
console.log(Reflect.deleteProperty(obj, 'age'));  // true
console.log(Reflect.ownKeys(obj));  // [ 'name' ]