Java Abstract Class
An abstract class is a class that is declared by
using the abstract keyword
. It may or may not have abstract
methods. Abstract classes cannot be instantiated, but they can be extended into
Java provides a special type of class called an abstract class. Which helps us to organize our classes based on common methods. An abstract class lets you put the common method names in one abstract class without having to write the actual implementation code.
An abstract class can be extended into sub-classes, these sub-classes usually provide implementations for all of the abstract methods.
The key idea with an abstract class is useful when
there is common functionality that's like to implement in a superclass
and some behavior is unique to specific classes. So you implement the superclass
as an abstract class and define methods that have common subclasses. Then you
implement each subclass by extending the abstract class and add the methods
unique to the class.
Points of abstract class :
- Abstract class contains abstract methods.
- Program can't instantiate an abstract class.
- Abstract classes contain mixture of non-abstract and abstract methods.
- If any class contains abstract methods then it must implements all
the abstract methods of the abstract class.