Inheritance in C++

Inheritance is an important concept in object-oriented programming (OOP) that allows you to create new classes based on existing classes. In C++, inheritance provides a mechanism for code reuse and allows you to establish relationships between classes. With inheritance, you can create a hierarchy of classes where derived classes inherit properties and behaviors from their base classes. In this lesson, we'll explore how inheritance works in C++ and how you can use it to design more modular and reusable code.

Base Classes and Derived Classes

In C++, a base class is the class from which other classes (called derived classes) inherit. The base class contains common properties and behaviors that are shared by the derived classes. When a derived class inherits from a base class, it automatically inherits the members (variables and functions) of the base class, except for its constructors and destructors.

class BaseClass {
public:
    int baseVariable;
    
    void baseMethod() {
        // Code for the base method
    }
};

class DerivedClass : public BaseClass {
public:
    int derivedVariable;
    
    void derivedMethod() {
        // Code for the derived method
    }
};

int main() {
    DerivedClass obj;
    
    obj.baseVariable = 10;        // Accessing the base class member
    obj.baseMethod();             // Calling the base class method
    obj.derivedVariable = 20;     // Accessing the derived class member
    obj.derivedMethod();          // Calling the derived class method
    
    return 0;
}

Types of Inheritance

C++ supports different types of inheritance, including:

• Single Inheritance: In single inheritance, a derived class inherits from a single base class.
• Multiple Inheritance: In multiple inheritance, a derived class inherits from multiple base classes.
• Multilevel Inheritance: In multilevel inheritance, a derived class inherits from a base class, and another class inherits from the derived class, forming a chain of inheritance.
• Hierarchical Inheritance: In hierarchical inheritance, multiple derived classes inherit from a single base class.
• Hybrid Inheritance: Hybrid inheritance is a combination of multiple inheritance and multilevel inheritance.

Conclusion

Inheritance is a powerful feature in C++ that allows you to create new classes based on existing classes. It provides a way to establish relationships between classes, promote code reuse, and design more modular and reusable code. With inheritance, you can create hierarchies of classes, where derived classes inherit properties and behaviors from their base classes. Understanding inheritance is crucial for mastering object-oriented programming in C++. Keep practicing and exploring different inheritance techniques to enhance your programming skills.