friend function code example
Example 1: friend function
#include
using namespace std;
class Box
{
private:
int length;
public:
Box (): length (0) {}
friend int printLength (Box); //friend function
};
int printLength (Box b)
{
b. length +=10;
return b. length;
}
int main ()
{
Box b;
cout <<” Length of box:” <
Example 2: friend function
#include
using namespace std;
class B; //forward declaration.
class A
{
int x;
public:
void setdata (int i)
{
x=i;
}
friend void max (A, B); //friend function.
} ;
class B
{
int y;
public:
void setdata (int i)
{
y=i;
}
friend void max (A, B);
};
void max (A a, B b)
{
if (a.x >= b.y)
std:: cout<< a.x << std::endl;
else
std::cout<< b.y << std::endl;
}
int main ()
{
A a;
B b;
a. setdata (10);
b. setdata (20);
max (a, b);
return 0;
}