ng4-service.ts

// cli 
ng g service myData


//my-data.service.ts
constructor() { }

  obj = {
      id:"1",
      name:"open",
      rollno:"2233"
  }


  success(){return "Successful" ;}





//app.module.ts
import { MyDataService } from './my-data.service';

providers: [MyDataService],




//app.component.ts

import { MyDataService } from './my-data.service';

constructor(private newServices: MyDataService){}

  ngOnInit(){
      console.log(this.newServices.success());
       console.log(this.newServices.obj);
  }


//cli
ng g c product



//product.component.ts  
import { MyDataService } from './../my-data.service';
constructor(private newServices: MyDataService){}

  ngOnInit(){
       console.log(this.newServices.success());
       console.log(this.newServices.obj.name);
  }