Virtual function vs pure virtual function :
Virtual function :-
1. Virtual function have a function body.
2. Overloaded can be done by the virtual funciton.
(Optional)
3. It is define as : virtual int myfunction();
virtual function example
---code---
class a
{
public:
virtual void imvirtualmethod()
{
cout<<"Hello";
}
};
class b:public a
{
public:
void imvirtualmethod()
{
cout<<"Nishant";
}
};
// main starts from here
void main()
{
clrscr();
a *ptr;
a obj; // object of class a
b obj1; // object of class b
ptr = &obj;
p->imvirtualmethod(); //calling virtual method of class a
ptr = &obj1;
ptr->imvirtualmethod(); //calling virtual method of class b
getch();
}
/---code---
Pure virtual function :-
1. Pure virtual function have no function body.
2. Overloading is must in pure virtual funciton. (Must)
3. It is define as : virtual int myfunction() = 0;
4. A class is "abstract class" when it has at least one
pure virtual function.
5. You cann't create instance of "abstract class", rather
you have to inherit the "abstract class" and overload all
pure virtual function.
pure virtual function example
---code---
class a
{
public:
virtual void imvirtualmethod() = 0; //declaration of pure
virtual method
};
class b:public a
{
public:
void imvirtualmethod()
{
cout<<"hello";
}
};
class c:public b
{
public:
void imvirtualmethod()
{
cout<<"Nishant";
} };
// main starts from here
void main()
{
clrscr();
a *ptr;
c obj; // object of class c
b obj1; // object of class b
ptr = &obj;
p->imvirtualmethod(); //calling override virtual
method of class c
ptr = &obj1;
ptr->imvirtualmethod(); //calling override virtual
method of class b
getch();
}
/---code---
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