{
 let readonly=function(target,name,descriptor){
 descriptor.writable=false;return descriptor
 };

 class Test{
 @readonly
 time(){ return '2017-03-11'}
 }

 let test=new Test(); // test.time=function(){
 // console.log('reset time');
 // }; 將報(bào)錯 如果修改的話
 console.log(test.time());
}

{
 let typename=function(target,name,descriptor){
 target.myname='hello';
 }

 @typename
 class Test{

 }

 console.log('類修飾符',Test.myname);//hello // 第三方庫修飾器的js庫：core-decorators; npm install core-decorators}

{
 let log=(type)=>{return function(target,name,descriptor){
 let src_method=descriptor.value;
 descriptor.value=(...arg)=>{
 src_method.apply(target,arg);
 console.info(`log ${type}`);
 }
 }
 }

 class AD{
 @log('show')
 show(){
 console.info('ad is show')
 }
 @log('click')
 click(){
 console.info('ad is click');
 }
 }

 let ad=new AD();
 ad.show();
 ad.click();
}