Why stateful/stateless widgets extends and doesn't implements?

Question

I have this question for a job interview, and i want to know why the stateful and staless widgets, use extends and why not use implements in Flutter/Dart?

Answer 1

Extends

extends is usually the go-to when you want to make a more specific version of a class.

When you extend a class, you inherit all properties, methods, etc. If you want to override a method, you prefix the method with @override.

Implements

implements is when you want to make a whole new version of a class but you want to inherit the class type.

When you create a new implementation of a class, you are responsible for supplying everything necessary to make that class function.