Abstract classes and interfaces in Java serve fundamentally ... The template method pattern manipulates instance variables within concrete methods. From an object-oriented programming perspective ...

Learn the four types of polymorphism in Java, then start using subtype polymorphism to execute different forms of the same Java method ... instantiated), and abstract methods (which cannot ...

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 is made into a generic class ...