change the class based on value in angular code example
Example 1: Angular 8 ngClass If
[ngClass]="{'my-class': step=='step1'}"
Example 2: Angular add class dynamically
<button
*ngFor="let button of buttons"
class="general"
(click)="ChangeScreen(button.label)"
[class.selected]="CurrentPage == button.label">
{{ button.label }}
</button>