Explain the abstract keyword or the abstract method in Object-oriented programming

In object-oriented programming, the abstract keyword plays a crucial role in achieving abstraction, a key concept for code organization and flexibility. It can be applied to both classes and methods, with slightly different effects:

1. Abstract Classes:

• Definition: A class declared with the abstract keyword is an incomplete blueprint that cannot be directly instantiated (meaning you can't create objects from it).
• Purpose: It serves as a template for subclasses that inherit its properties and behavior. These subclasses then provide concrete implementations for any abstract methods in the parent class. This allows for common functionality to be shared while leaving room for specific variations in its subclasses.
• Example: Let's say you have an abstract class named Shape with an abstract method draw(). This means Shape itself cannot be used to draw anything, but it forces any subclass (Circle, Square, etc.) to implement its own draw() method, specifying how it should be drawn on the screen.

2. Abstract Methods:

• Definition: A method declared with the abstract keyword provides a signature (name, parameters, return type) but no implementation. The actual code for the method is left to be defined by its subclasses.
• Purpose: It enforces consistency across subclasses by ensuring they all fulfil the required functionality while allowing them to customize the implementation details.
• Example: In the Shape example, the draw() method is abstract. Each subclass (Circle, Square) then implements its own version of draw(), specifying how its specific shape should be drawn.

Benefits of using abstract classes and methods:

• Code reusability: Shared functionality is defined once in the abstract class and inherited by subclasses, avoiding redundant code.
• Flexibility: Subclasses can specialize the behavior of inherited methods or define new ones, adapting to specific needs.
• Code organization: Abstraction helps modularize code by grouping related functionalities in appropriate classes and interfaces.

Overall, the abstract keyword is a powerful tool for building flexible and organized object-oriented programs. It helps programmers focus on defining common aspects while allowing specific details to be handled by different subclasses.