What Is Virtual Function In Cpp?

A virtual function is a member function that is declared within a base class and redefined by a derived class. By declaring a virtual function, the base class establishes a new polymorphic type. The C++ programming language uses virtual functions to support run-time polymorphism.

What is virtual function?

A virtual function is a member function that is declared within a base class and redefined by a derived class. When a program invokes a virtual function, the run-time system first looks up the address of the virtual function in the vtable, and then calls the function.

What are the benefits of virtual function?

There are many benefits of using virtual functions in C++. First, they allow you to write code that is more flexible and extensible. You can easily add new functionality to existing code without having to change the function signatures. Second, virtual functions make it easy to write code that is portable across different compilers and platforms. Third, virtual functions can improve performance by allowing the compiler to optimize the code better. Finally, virtual functions can help you to avoid potential bugs by making sure that all the derived classes implement the same interface.

How to declare a virtual function in C++ programming language?

A virtual function is a function that is declared within a base class and is later redefined by a derived class. It is often used to enable polymorphism, which is the ability of different objects to respond differently to the same method call.

To declare a virtual function in C++, simply prepend the keyword virtual to the method’s declaration inside the base class:

virtual void someMethod();

When someMethod() is called on an object, the compiler will check to see if it has been redefined in any derived classes. If so, the derived class’s version of someMethod() will be executed; if not, the base class’s version will be executed.

What is the difference between a pure virtual function and a regular virtual function?

A pure virtual function is a function that is declared but not defined. A regular virtual function is a function that is both declared and defined.

How to call a virtual function in C++?

When you want to call a virtual function in your code, you need to prefix the function name with the scope resolution operator (::) and the class name. For example, if you have a class named MyClass with a virtual function named MyFunction, you would call the function like this:

MyClass::MyFunction();

Conclusion

Virtual functions are an important part of the C++ programming language. They allow you to create programs that are more flexible and easier to maintain. If you haven’t used virtual functions before, I hope this article has helped you understand what they are and how they can be used.