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.

An abstract class is a class that is declared abstract using the abstract keyword. It may or may not include abstract methods. Abstract classes cannot be instantiated, but they can be subclassed.

3) Abstract class can have final, non-final, static and non-static variables. Interface can't provide the implementation of abstract class. 5) The abstract keyword is used to declare abstract class.

Keywords const vs. final in Java. The final keyword can be considered the Java languages equivalent for const.. If a Java developer wants a variable to be constant, they mark that variable as final.A ...