What is virtual function

What is virtual function?

Answer:

When derived class overrides the base class method by redefining the same function, then if client wants to access redefined the method from derived class through a pointer from base class object, then you must define this function in base class as virtual function.

class parent

{

void Show() {

cout << "i'm parent" << endl;

} };

class child: public parent {

void Show() {

cout << "i'm child" << endl;

} };

parent * parent_object_ptr = new child;

parent_object_ptr->show() // calls parent->show() i

now we goto virtual world...

class parent { virtual void Show() {

cout << "i'm parent" << endl;

} };

class child: public parent { void Show() {

cout << "i'm child" << endl;

} };

parent * parent_object_ptr = new child;

parent_object_ptr->show() // calls child->show()