Classes are not base class of itself. Every class in Java is a derived class. Every class in Java has 'Object' as the Superclass. The Object class is the only class in JAVA that has no Superclass!
A base class is a class that a derived class is based on. All of the methods and attributes of the base class are included in the derived class, with the methods and attributes of the derived class...
An abstract class cannot have a constructor and hence you cannot invoke the constructor of the class - i.e., you can instantiate an abstract class and hence you cannot call the constructor of an...
Yes, the derived class includes the memory of the base class. The derived class inherits everything in the base class, data and function, and provides additional data and function as needed.