Decorators  In order to use decorators in our code, make sure that in tsconfig file,  "target": "es5",    ,"experimentalDecorators": true,      function   Logger ( constructor :  Function ){        console . log ( "Logging..." );        console . log ( constructor );   }    @ Logger   class   Person  {        name  = "TEJA" ;        constructor (){            console . log ( "creating a person object..." );       }   }   const   pers  =  new   Person ();   console . log ( pers );     Factory Decorator:   From the above example, In Logger function, we have used one more constructor function   and call it via decorator. Therefore it help to call the class by default in app.ts and also we can call other set of functions on load.     function   Logger ( logString :  string...