import { Component } from '@angular/core';
import { Observable } from 'rxjs';
 
@Component({
  selector: 'app-stopwatch',
  templateUrl: './stopwatch.component.html'
})
export class StopwatchComponent {
 
  stopwatchValue: number;
  stopwatchValue$: Observable;
 
  start() {
    this.stopwatchValue$.subscribe(num =>
      this.stopwatchValue = num
    );
  }
}