comment utiliser caché dans div dans angulaire

<div *ngIf="edited" class="alert alert-success box-msg" role="alert">
        <strong>List Saved!</strong> Your changes has been saved.
</div>

<div [hidden] = "email.valid || email.pristine" class="alert alert-danger" >
            Email is required !!!
        </div>
Cheerful Caribou