{"id":11457,"date":"2022-12-29T04:13:02","date_gmt":"2022-12-29T04:13:02","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=11457"},"modified":"2023-11-28T04:37:25","modified_gmt":"2023-11-28T04:37:25","slug":"friend-function-in-cpp","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/friend-function-in-cpp\/","title":{"rendered":"Friend Function in C++"},"content":{"rendered":"

*\"\"<\/p>\n

In C++, a friend function stands as a distinct category of function that, although not part of a class, enjoys privileged access to the private and protected members of that class. This special permission enables the friend function to operate on the internal aspects of the class as if it were an integral member function. Declarations for friend functions are typically made within the class to which they extend their friendship, and they are commonly employed to carefully expose controlled external access to the attributes of the class. While friend functions provide a means to interact with private members, their utilization should be deliberate and confined to situations where preserving encapsulation is of utmost importance. Let’s delve deeper into the intricacies of friend functions in C++.<\/p>\n

What is a Friend Function in C++?<\/h2>\n

A friend function in C++<\/strong> is a special function which can access private and protected members of a class even though it is not a member function of the class.<\/p>\n

It is declared as a friend using the \u2018friend\u2019<\/strong> keyword inside the class. By declaring the function as a friend friend in C++<\/strong> all the permission can be granted to the function. \u2018friend\u2019<\/strong> keyword is placed only inside the class when the function is declared as a friend function, not in the function definition.<\/p>\n

We don\u2019t have to use the name of the object or dot operator during the calling of the function, a friend function in C++<\/strong> can accept the object of the class where the function is declared as a friend function in C++<\/strong> as an argument. Friend function in C++<\/strong> can be declared in any section of the class i.e. public or private or protected.<\/p>\n

Syntax of friend function in C++:<\/h2>\n
class     \n{    \n    friend    (argument\/s_type);  \n};<\/code><\/pre>\n
Characteristics of Friend Function in C++:<\/h2>\n
    \n
  • The function is not in the scope of the class to which it has been declared as a friend.<\/li>\n
  • It cannot be called using the object as it is not in the scope of that class.<\/li>\n
  • It can be invoked like a normal function without using the object.<\/li>\n
  • It cannot access the member names directly and has to use an object name and dot membership operator with the member name.<\/li>\n
  • It can be declared either in the private or the public part of the class.<\/li>\n<\/ul>\n
    Types of Friend Function<\/h2>\n
    A friend function in C++ can be of two types:<\/strong><\/p>\n
    Global function as friend function in C++<\/h3>\n
    Global Functions<\/strong> in C++ are the functions that are declared outside of any class, function or namespace. Global Functions<\/strong> are also called free functions.<\/strong>
    \nExamples of Global Function in C++<\/strong> as a friend function in C++<\/strong> :<\/p>\n
      \n
    1. \n
      Global functions<\/strong> as a friend function in C++ example<\/strong> to only one class to find the  product of two numbers.
      \n\t\t\t\t\t\t