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.

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 ...

Get started with polymorphism in Java and how to do method invocation in polymorphic method calls.

Suppose we have ten such local stateful objects in class, then we need ten abstract methods for the sole purpose of enabling unit-testing. It indeed makes unit-testing possible and simple – at the ...