ngclass angular 2,...,5,..,7 examples with conditions

Angular 2,..,7 provides several ways to add classes conditionally:

type one

[class.my-class]="step=='step1'"

type two

[ngClass]="{'my-class': step=='step1'}"

and multiple option:

[ngClass]="{'my-class': step=='step1', 'my-class2':step=='step2' }"

type three

[ngClass]="{1:'my-class1',2:'my-class2',3:'my-class4'}[step]"

type four

[ngClass]="(step=='step1')?'my-class1':'my-class2'"