Angular: conditional class with *ngClass

Question

What is wrong with my Angular code? I am getting:

Cannot read property \'remove\' of undefined at BrowserDomAdapter.removeClass ...

Answer 1

Angular version 2,...,9 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'"