What is Friend?
A friend is Special One
What is the difference between a friend and a non-friend?
A friend has privileges to your private and protected stuff

What is Friend Function
A friend function in C++ is a function that is preceded by the keyword “friend”. When the function is declared as a friend, then it can access the private and protected data members of the class.
Characteristics of a Friend function:
- The function is not in the scope of the class to which it has been declared as a friend.
- It cannot be called using the object as it is not in the scope of that class.
- It can be invoked like a normal function without using the object.
- It cannot access the member names directly and has to use an object name and dot membership operator with the member name.
- It can be declared either in the private or the public part.
/*
Objective: Demonstrate Friend Fucntion
*/
#include <iostream.h>
#include <conio.h>
class Box
{
private:
int width;
public:
void setData(int x)
{
width=x;
}
friend void display(Box b);
};
void display(Box b)
{
cout<<"I am box and my width is "<<b.width<<endl;
}
void main()
{
clrscr();
Box b1;
b1.setData(100);
display(b1);
getch();
}
Friend Function in C++