Swap - ngClass

Code

<button class={"prev " + (this.start === 0? 'disabled' : '')}></button>

Context

Think of this as a button, that is part of a pagination component. If, the user is at the start of the list, then the Previous button i.e. ( button with the class '.prev' ) should be disabled.

With Angular, we would generally use ngClass.

The alternative with StencilJS is to use a Data binding expression, based on the value of the 'start' variable. This then allows you to add as many classes as need be.

Reference

how to handle ngClass in stencils JS web componentsStack Overflow