Multiple classes:
<div class="user--status" [ngClass]="{ 'user--status-active': user?.status === 'active', 'user--status-inactive': user?.status === 'inactive' }"> {{ user?.status }} </div>
Conditional class:
<div class="user--status" [ngClass]="user?.status == 'active' ? 'user--status-active' : 'user--status-inactive'"> {{ user?.status }} </div>