What is a Friend function in C++?Please explain in an easy way :')

Answer 1

If you have

class X{
private:
int secret;
}

and a function

int getSecret(X& x){
return x.secret;
}

this program will error, because 'secret' is private. The solution is to define 'getSecret' as a friend.

class X{
private:
int secret;
public:
friend int getSecret(X&);
}

Now the function getSecret (and only getSecret) can access all the private members.

In my opinion there's never a good reason to use friend functions, so try to not use them too often.

Answer 2

https://www.programiz.com/cpp-programming/friend-function-class