What are virtual functions in C++ and Java?

What are virtual functions in C++ and Java?

Virtual functions are functions in a base class that can be overridden in derived classes. They enable polymorphism.

Can you give me an example of how virtual functions work in C++?

Sure! In C++, you declare a virtual function in the base class using the keyword 'virtual'. Here's a simple example:

class Base {
public:
    virtual void show() {
        cout << "Base class show function called.";
    }
};

class Derived : public Base {
public:
    void show() override {
        cout << "Derived class show function called.";
    }
};

When you call show() on a base class pointer pointing to a derived class object, the derived class's show() is executed.

How does this differ in Java?

In Java, all non-static methods are virtual by default. You can override them in derived classes without needing the 'virtual' keyword. Here's an example:

class Base {
    void show() {
        System.out.println("Base class show method called.");
    }
}

class Derived extends Base {
    @Override
    void show() {
        System.out.println("Derived class show method called.");
    }
}

Just like in C++, calling show() on a base class reference pointing to a derived class object will invoke the derived class's method.

What are the benefits of using virtual functions?

The main benefits of using virtual functions are:

1. Polymorphism: They allow for dynamic method resolution, enabling you to call derived class methods through base class pointers.
2. Code Reusability: You can write more generic and reusable code by relying on base class interfaces.