[ngClass]="{'my-class': step=='step1'}"
[ngClass]="(step=='step1')?'my-class1':'my-class2'"
<div [className]="isActive ? 'active' : 'inactive'"> </div>
<div [ngClass]="{'message': info.priority < 10, 'warn': info.priority > 10 && info.priority < 20, 'error': info.priority > 30}"> {{info.text}} </div>
[ngClass]="{'my-class': step=='step1', 'my-class2':step=='step2' }"
