import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable()
export class DataService {
  constructor(private http: HttpClient) {}

  getData(): Observable {
    return this.http.get('https://api.example.com/data').pipe(
      map(response => response.json())
    );
  }
}

export class MyComponent implements OnInit {
  data: any;

  constructor(private dataService: DataService) {}

  ngOnInit() {
    this.dataService.getData().subscribe(response => {
      this.data = response;
    });
  }
}