@if(hero) {
<div>
  <h2>{{ hero.name | uppercase }} Details</h2>
  <div><span>id: </span>{{ hero.id }}</div>
  <div>
    <label for="hero-name">Hero name: </label>
    <input id="hero-name" [(ngModel)]="hero.name" placeholder="name" />
  </div>
</div>
}
<button (click)="goBack()">go back</button>