C++

Friend Functions in C++

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Friend Functions in C++

Friend functions are a unique feature of C++ that allow functions to access private and protected data of a class. A friend function is a non-member function that is given access to the private and protected members of a class.

Declaring a Friend Function

To declare a friend function, the friend keyword must be used before the function prototype in the class declaration. Here’s an example:

class MyClass {
private:
    int privateVar;
public:
    friend void friendFunction(MyClass& obj);
};
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In this example, friendFunction is declared as a friend function of the MyClass class. This means that friendFunction can access the private members of MyClass.

Defining a Friend Function

To define a friend function, the friend keyword is not used. Instead, the function is defined like any other function outside the class definition. However, the function parameter list must include a reference to the class object that it is a friend of.

void friendFunction(MyClass& obj) {
    obj.privateVar = 10;
}
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In this example, friendFunction sets the private variable privateVar of MyClass to 10.

Using Friend Functions

Once a friend function is declared in a class, it can be used like any other function. Here’s an example:

MyClass obj;
friendFunction(obj);
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In this example, friendFunction is called with an instance of MyClass as a parameter.

Benefits of Friend Functions

Friend functions can be useful in situations where a function needs to access private or protected data of a class, but it does not make sense for that function to be a member function of the class. Friend functions can also be used to improve code readability and organization.

Drawbacks of Friend Functions

However, using friend functions can also make code more difficult to maintain and test. It can also increase the risk of accidental misuse of private data by making it more widely accessible.

Conclusion

Friend functions are a powerful feature of C++ that allow non-member functions to access private and protected members of a class. They can be useful in certain situations, but should be used with caution to avoid potential drawbacks.

xalgord
WRITTEN BY

xalgord

Constantly learning & adapting to new technologies. Passionate about solving complex problems with code. #programming #softwareengineering

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