blog--angular-reactive-forms--reactive-1.html

<form [formGroup]="addFriendForm" (ngSubmit)="onSubmit()">
  <input type="text" formControlName="name">
  <input type="text" formControlName="email">
  <button type="submit"
    [disabled]="!f.valid">Submit!</button>
</form>

// Component
public addFriendForm: FormGroup;
  constructor(formBuilder: FormBuilder) {
    this.addFriendForm = formBuilder.group({
      name: [user.name, Validators.required],
      email: [user.email, Validators.required]
  });
}