angular-mutationobserver4.example.ts

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html'
})
export class AppComponent {
  public todos: string[];

  constructor(private appService: AppService) {
    this.todos = ['Todo', 'Todo', 'Todo'];
  }

  addTodo(): void {
    this.appService
      .fetchData()
      .subscribe((todo: string) => this.todos.push(todo));
  }

  removeTodo(index: number): void {
    this.todos.splice(index, 1);
  }
}