‹div [ngSwitch]="hero?.emotion"›
  ‹app-happy-hero    *ngSwitchCase="'happy'"    [hero]="hero"›‹/app-happy-hero›
  ‹app-sad-hero      *ngSwitchCase="'sad'"      [hero]="hero"›‹/app-sad-hero›
  ‹app-confused-hero *ngSwitchCase="'app-confused'" [hero]="hero"›‹app-confused-hero›
  ‹app-unknown-hero  *ngSwitchDefault           [hero]="hero"›‹app-unknown-hero›
‹/div›