Friend function:

All members of the access specifiers public, private, and protected of a class can be accessed by a friend function.

• Friend functions are not the member functions of a class.
• The function prototype for the friend function is declared inside the class.
  • Even though the function is not considered as the member of the class.
• The keyword "friend" is used to represent that the function is the friend function.
• All non-friend functions of the class can access the public members in the class.
  • But the friend function of the class can access all the public, private, and protected members in the class.

Syntax:

The syntax of the friend function is as follows:

friend return_type function_name (parameter)

Example:

//Header file

#include <iostream>

using namespace std;

//class definition

class Teacher

{

//access specifier

private:

//declare the variable

int mark;

//access specifier

public:

//constructor

Teacher()

{

//set the value

mark=5;

}

//friend function

friend class Student;

//function definition

void t...