The QuizEditComponent features a very simple yet perfectly working form, hence it's perfect to become our guinea pig.
Open the quiz-edit.component.ts file and update it in the following way (new lines are highlighted):
import { Component, Inject, OnInit } from "@angular/core";import { FormGroup, FormControl, FormBuilder, Validators } from '@angular/forms';[...]export class QuizEditComponent { title: string; quiz: Quiz; form: FormGroup;[...] constructor(private activatedRoute: ActivatedRoute, private router: Router, private http: HttpClient, private fb: FormBuilder, @Inject('BASE_URL') private baseUrl: string) { // create an empty object from the Quiz interface this.quiz = <Quiz>{}; // initialize the form this.createForm(); ...