README.md

Redefining Base Class Methods in Inheritance

When using inheritance in C++, derived classes inherit the characteristics of the base class. This includes the methods defined in the base class. However, there are scenarios where the inherited behavior doesn't fit the needs of the derived class. In such cases, the derived class can redefine the base class methods to provide new functionality. This is commonly known as method overriding.

Overriding vs. Hiding

There are two ways to redefine a method in a derived class:

• Overriding: This is when the derived class has a method with the same signature as one in its base class. The derived method replaces the base method for objects of the derived class, even when accessed through a pointer or reference to the base.
• Hiding: This occurs when a derived class declares a method with the same name but a different signature. The base class method is hidden, not overridden, which can lead to different behavior when the method is called through the base class interface.

Overriding Methods

To override a method in a derived class:

1. Same Signature: The method must have the same signature as the one in the base class (same name, return type, and parameter list).
2. Virtual Keyword: The method in the base class should be marked with the virtual keyword to indicate that it's intended to be overridden.
3. Access Specifier: The access level (public, protected, private) of the overriding method can differ from that of the base class method.

Best Practices

• Use override Keyword: C++11 introduced the override keyword, which makes it clear that the method is meant to override a base class method. It also provides compile-time checks to avoid inadvertent method hiding.
• Maintain Is-A Relationship: When overriding a method, ensure that the derived class's method is substitutable for the base class's method, preserving the is-a relationship.
• Consistent Method Behavior: The overriding method should extend the base class behavior, not replace it entirely. It should be consistent with the expectations set by the base class's interface.

Example of Method Overriding

class Base {
public:
    virtual void show() {
        std::cout << "Show Base" << std::endl;
    }
};

class Derived : public Base {
public:
    // Override the 'show' method of the base class
    void show() override {
        std::cout << "Show Derived" << std::endl;
    }
};

In the above example, the Derived class overrides the show method from the Base class. When show is called on a Derived object, even if it's through a pointer or reference to Base, the Derived class's version of show will be executed.

Conclusion

Redefining base class methods through overriding is a fundamental concept in object-oriented programming that allows for polymorphic behavior. It enables derived classes to customize or enhance the functionality provided by their base classes, leading to flexible and maintainable code structures. When overriding methods, it is essential to follow the language rules and best practices to ensure that the behavior is as expected and to make use of the type checking provided by the compiler.