Hi all Why do I need parentheses at the end of the following inheritance: ```class NoInterestsFound ...

# getting-started

[zero_coding]

Hi all
Why do I need parentheses at the end of the following inheritance:

class NoInterestsFound : RuntimeException()

[Casey Brooks]

They signify that you’re extending a class. If you omit the parentheses, you’re implementing an interface. Since RuntimeException is a class, it is being extended and requires the parentheses as it is effectively calling the superclass constructor

[Tobias Berger]

Because RuntimeException is a class and you have to call its constructor. It's like calling super() in the first line of a Java constructor, kotlin just forces you to do it explicitly.

[Tobias Berger]

as there are no keywords like extends and implements in kotlin, I'd say it's also very useful as a differentiation between interfaces and superclasses (as @Casey Brooks said)

[zero_coding]

Thanks a lot guys