friend function in c++ - InTerestinG321

friend function in c++


Friend function:
Friend function access all private and protected data member of the class when it has a friend. To declared as friend function, must include it’s prototype within the class and also include keyword friend.

Ex:

#include <iostream>
Using namespace std;
Class sum
{
Int a,b;
Public:
Friend int sum(); // declared as friend
Void set_ab(int i,int j);
};
Void sum :: set_ab(int I,int j)
{
a=i;
b=j;
}
Int sum() /* because we declared sum()is friend of class sum, direct access a and b */
{
Int x;
x.a + x.b;
}
Int main()
{
Sum s;
s.set_ab(20,30);
cout<<return 0;
}

You can notice that sum() is not a member of class sum, but it still all rights to access its private members, and also noticed that the sum() is called without use of dot operator.


 General form
Class 
Function

2 comments: