Derived Class

What does Derived Class mean?

In Object-Oriented Programming (OOP), a derived class is a class that inherits the properties and methods of another class, known as a base class or superclass. This inheritance mechanism allows the derived class to extend or modify the functionality of the base class, creating a more specialized or customized version.

Derived classes inherit all the non-private members of the base class, including data members, member functions, and constructors. They can also define their own unique members to add additional functionality or Override inherited members to modify their behavior. By reusing and extending the code of the base class, derived classes promote code reusability, reduce code duplication, and enhance maintainability.

The relationship between a derived class and its base class is known as an “is-a” relationship. This means that the derived class is a specialized type of the base class. For example, if a base class represents the concept of a “vehicle,” a derived class could represent a specific type of vehicle such as a “car.” The car class would inherit the general properties and methods of a vehicle, such as its ability to move, but it could also define additional members specific to cars, such as the number of wheels or the fuel type.

Derived classes play a crucial role in OOP by enabling the creation of class hierarchies that represent real-world entities and relationships. They allow developers to organize code into a logical and hierarchical structure, making it easier to manage complexity and create flexible and extensible software systems.

Applications

Derived classes are extensively used in various software development applications:

• Code Reusability: Derived classes allow developers to reuse code from existing classes, reducing code duplication and development time. By inheriting from a base class, derived classes can leverage common functionality and focus on implementing specialized or unique features.

• Polymorphism: Polymorphism, the ability of objects to behave differently based on their class, is facilitated by derived classes. Derived classes can override inherited methods with their own implementations, allowing for different behaviors when invoked through the base class reference. This enables flexible and dynamic programming.

• Extensibility and Customization: Derived classes allow for easy extensibility of existing classes. Developers can create specialized versions of base classes by adding new functionality or modifying inherited behavior, without modifying the base class itself. This promotes loose coupling and facilitates software evolution.

• Class Hierarchies: Derived classes enable the creation of class hierarchies that represent real-world entities and relationships. They organize code into a logical and hierarchical structure, making it easier to manage complexity and foster code reusability.

History

The concept of derived classes emerged with the development of object-oriented programming (OOP) languages such as Simula 67 and Smalltalk in the 1960s and 1970s. These languages introduced the idea of inheritance, which allowed classes to inherit properties and methods from other classes.

The development of the C++ programming language in the 1980s popularized the concept of derived classes. C++ introduced the concept of multiple inheritance, allowing derived classes to inherit from multiple base classes, and virtual functions, which enabled dynamic binding and polymorphism.

Since then, derived classes have become a fundamental concept in OOP languages. They are widely used in software development to enhance code reuse, promote extensibility, and facilitate the creation of complex and flexible software systems.