Examples discussion

example1.ts

class Component {
    data$ = this.service.getData();
    constructor(private service: Service) { }
}

class Component {
    data$: Observable<Data>;

    constructor(private service: Service) {
      this.data$ = service.getData();
    }
}
      
      
class Component implements OnInit {
    data$: Observable<Data>;

    constructor(private service: Service) {}
      
    ngOnInit() {
      this.data$ = service.getData();
    }
}