//Proxy,Reflect

 {

     let obj={

         time:'2018-06-25',

         name:'net',

         _r:123

     };

     let monitor = new Proxy(obj,{

         //拦截对象属性的读取

         get(target,key){

             return target[key].replace('2018','2019')

         },

         //拦截对象设置属性

         set(target,key,value){

             if(key==='name'){

                 return target[key]=value;

             }else{

                 return target[key];

             }

         },

         //拦截key in object 操作

         has(target,key){

             if(key==='name'){

                 return target[key];

             }else{

                 return false;

             }

         },

         //拦截delete

         deleteProperty(target,key){

             if(key.indexOf('_')>-1){

                 delete target[key];

                 return true;

             }else{

                 return target[key]

             }

         },

         //拦截Object.keys,Object.getOwnPropertySymbols,Object.getOwnPropertyNames

         ownKeys(target){

             return Object.keys(target).filter(item=>item!='time')

         }

     });

     console.log('get',monitor.time);

     monitor.name='web';

     console.log('set',monitor.name);

     console.log('has','name' in monitor);

     // delete monitor.time;

     // console.log('delete',monitor);

     // delete monitor._r;

     // console.log('delete',monitor);

      console.log('ownKeys',Object.keys(monitor));

 }

 {

     let obj={

         time:'2018-06-25',

         name:'net',

         _r:123

     };

     console.log('Reflect get',Reflect.get(obj,'time'))

     console.log('Reflect set',Reflect.set(obj,'time','2019-06-05'))

     console.log(obj);

     console.log('has',Reflect.has(obj,'name'))

 }

 //例子

 {

     function validator(target,validator){

         return new Proxy(target,{

             _validator:validator,

             set(target,key,value,proxy){

                 if(target.hasOwnProperty(key)){

                     let va=this._validator[key];

                     if(!!va(value)){

                         return Reflect.set(target,key,value,proxy)

                     }else{

                         throw Error(`不能设置${key}到${value}`)

                     }

                 }else{

                     throw Error(`${key} 不存在`)

                 }

             }

         })

     }

     const personValidators={

         name(val){

             return typeof val==='string'

         },

         age(val){

             return typeof val==='number'&&val>18

         }

     }

     class Person{

         constructor(name,age){

             this.age=age;

             this.name=name;

             return validator(this,personValidators)

         }

     }

     const person = new Person('lilei',30);

     console.info(person)

     person.name="qqq qq";

     console.info(person)

 }