import { Component , OnInit } from '@angular/core' ; @ Component ( { selector : 'app-root' , templateUrl : './app.component.html' , styleUrls : [ './app.component.css' ] } ) export class AppComponent implements OnInit { subscription1Data = [ ] ; subscription2Data = [ ] ; subscription3Data = [ ] ; constructor ( ) { } ngOnInit ( ) { } subscribe1 ( ) { } subscribe2 ( ) { } subscribe3 ( ) { } }