Question

I am now studying a java and I’m at the part of Abstract.
I read sorta strange part to me that there is an abstract class
which does not include any abstarct method.

Why do they use this kind of class?

Answer 1

To prevent instantiation of that class and use it only as a base class. Child classes can use the general methods defined in the abstract class.

For example it doesn’t make sense to create an instance of AbstractVehicle. But All vehicles can reuse a common registerMileage(int) method.