---
title: "What is a friend function?"  
description: "What is a friend function?"  
author: "Shikhar Arora"  
published: 2019-12-07  
canonical: https://answers.mindstick.com/qa/92532/what-is-a-friend-function  
category: "technology"  
tags: ["software engineering", "programming language"]  
reading_time: 2 minutes  

---

# What is a friend function?

What is a [friend function](https://www.mindstick.com/forum/159857/please-provide-sample-code-of-friend-function-in-c-plus-plus)

## Answers

### Answer by Rahul Roi

## Friend class and function in C++

However, A [function](https://www.mindstick.com/articles/43970/purchase-suitable-wedding-dresses-for-your-wedding-function) is defined as a friend function in C++, then the protected and private data of a class can be accessed using the function.

Using the keyword friend compiler shows that the given function is the friend function. To access data in this way, a friend function must be declared inside the body of a class starting with the keyword friend. **Friend Class** Where a friend class can access private and protected members of other class in which it is declared as friend. This is sometimes useful to allow a particular class to access private members of other class. Like this, a LinkedList class may be allowed to access private members of Node. Declaration of friend function in C++

```
class class_name
{
    friend data_type function_name(argument/s);            // syntax of friend function.
};    
```

Characteristics of a Friend function:

- A function is not in the scope of the class to which it has been declared as a friend.
- That can't be called using the object as it is not in the scope of that class.
- That can be invoked like a normal function without using the object.
- That cannot access the member names directly and has to use an object name and dot membership operator with the member name.
- This can be declared either in the private or the public part.

Following are some important points about friend functions and classes:

- The Friend function should be used only for limited purpose. The too much functions or external classes are declared as friends of a class with protected or private data, it lessens the value of encapsulation of separate classes in OOPs(object-oriented programming).
- The Friendship is not mutual. When class A is a friend of B, then B doesn’t become a friend of A automatically.
- The Friendship is not inherited (See this for more details)
- That is the concept of friends is not there in Java.

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Original Source: https://answers.mindstick.com/qa/92532/what-is-a-friend-function

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