What are some examples of function overriding in C++?

What are some examples of function overriding in C++?

Function overriding in C++ allows a derived class to provide a specific implementation of a function that is already defined in its base class. Here are a few examples:

1. Base Class: class Animal { public: virtual void sound() { cout << "Animal sound"; } }; Derived Class: class Dog : public Animal { public: void sound() override { cout << "Bark"; } };

2. Base Class: class Shape { public: virtual void draw() { cout << "Drawing shape"; } }; Derived Class: class Circle : public Shape { public: void draw() override { cout << "Drawing circle"; } };

Would you like more examples or details on how it works?

Yes, can you explain how the override keyword works?

The override keyword in C++ is used to indicate that a member function is intended to override a virtual function in a base class. It helps catch errors at compile time if the function does not actually override any base class function. For example:

class Base { public: virtual void func() { } };
class Derived : public Base { public: void func() override { } }; // Correct
class WrongDerived : public Base { public: void func(int) override { } }; // Error: does not override

Using override makes your code safer and clearer.

What happens if I don't use the override keyword?

If you don't use the override keyword, the function will still override the base class function as long as the signatures match. However, if there is a mismatch in the function signature (like changing the parameter types), the compiler won't give you an error, and you might unintentionally create a new function instead of overriding the base class function. This can lead to bugs that are hard to track down.

Can you give me a real-world scenario where function overriding is useful?

Certainly! A real-world scenario for function overriding is in a graphics application where you have different shapes. You can have a base class Shape with a virtual function draw(). Each derived class like Circle, Square, and Triangle can override the draw() function to provide specific drawing logic for that shape. This allows you to treat all shapes uniformly while still having their unique behaviors when drawn.