C++ Friend function | C++ Friend function Programming Language | C++ Friend function With Example

C++ Friend function

A function is defined as a friend function in C++, then the protected and private data of a class can be accessed using the function.

By using the keyword friend compiler knows the given function is a friend function.

For accessing the data, the declaration of a friend function should be done inside the body of a class starting with the keyword friend.

Fig: C++ Friend function

Syntax:

class MCA

{

private:

data member;

public :

friend return type functionname(argument list)

};

Program:

#include<iostream.h>

#include<conio.h>

class MCA;

class mca

{

int  a,b;

public:

void getvalue()

{

a=20;

b=30;

}

friend void sum(MCA, mca);

};

class MCA

{

int x,y;

public:

void getvalue()

{

x=50;

y=70;

}

friend voidsum(MCA,mca);

};

void sum(MCA u,mca v)

{

int m,n;

m=v.a+u.x;

n=v.b+u.y;

cout<<m<<n;

}

void main()

{

MCA a1;

mca a2;

a1.getvalue();

cout<<”class mca call”;

a2.getvalue();

sum(a1,a2);

getch();

}

 

Output:

Call mca call 70 100