Угловой 8 ngclass if
[ngClass]="(step=='step1')?'my-class1':'my-class2'"
GrepperFoo69
[ngClass]="(step=='step1')?'my-class1':'my-class2'"<div [className]="condition ? 'example-class' : 'other-class'"></div>[ngClass]="{1:'my-class1',2:'my-class2',3:'my-class4'}[step]"