abstract class

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An abstract class is a foundational construct in object-oriented programming (OOP) languages that cannot be instantiated on its own but serves as a blueprint for other classes. Abstract classes are used to define interfaces with a mix of implementations for some methods and abstraction for others. Essentially, they allow you to create a set of methods that must be created within any child classes built from the abstract class.

Key Characteristics:

  • Instantiation: Abstract classes cannot be instantiated directly. Instead, they require a subclass to provide implementations for the abstract methods before an instance of the subclass can be created.
  • Method Definitions: They can contain both abstract methods (which have no body and must be implemented by subclasses) and concrete methods (which have their implementation in the abstract class).
  • Inheritance: Abstract classes are designed to be inherited by subclasses. The subclass must implement all abstract methods but can also override concrete methods.

Purpose and Use:

  • Code Reusability and Modularization: Abstract classes allow programmers to reuse the code for the common methods implemented in the abstract class and require specific implementations only for the abstract methods in the subclass.
  • Design and Planning: They provide a clear template for what classes inheriting from them should look like and what methods and attributes they must implement, facilitating better software design and planning.
  • Enforcing a Contract for subclasses: By defining abstract methods, an abstract class enforces a contract with its subclasses, ensuring that certain methods are implemented in the subclass.

Abstract classes are a crucial part of object-oriented programming, providing a way to define interfaces for a set of classes. They enforce a structure while allowing flexibility in how subclasses implement their methods. Abstract classes promote code reusability, enforce standardization, and facilitate clearer, more maintainable code design.

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