Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Except for the Object class, a class has exactly one direct superclass. A class inherits fields and methods from all its superclasses, whether direct or indirect. A subclass can override methods that ...

Learn to use method overriding and abstract classes to achieve dynamic polymorphism in Java, a feature that allows different implementations of the same method.

Write a program with one abstract class and two normal classes that extend from the abstract class. Create attributes, abstract methods and normal methods in each and then call the methods and print ...

In Classes and objects in Java, you learned how to declare static fields and static methods as members of a class, and in Class and object initialization in Java, you learned how to declare static ...

What is an abstract class? An abstract class is a template definition of methods and variables in a specific class, or category of objects. In programming, objects are units of code, and each object ...

Our second big rule about using abstract concerns the relationship between abstract method and the classes in which the are defined. If a class defines any abstract methods (or, as we will see, ...