![Friend Function in C++
Understanding Access Privileges
Beyond Class Boundaries
Presented by: [Your Name]](https://image.slidesharecdn.com/friendfunctionincpp-250503045913-d5fdcfd6/85/Friend_Function_in_CPP-its-use-and-examples-1-320.jpg)
Friend_Function_in_CPP its use and examples.
- 1. Friend Function in C++ Understanding Access Privileges Beyond Class Boundaries Presented by: [Your Name]
- 2. Introduction • C++ supports Encapsulation by restricting access to class members. • But sometimes, we need external functions to access private or protected members. • This is where friend functions come in.
- 3. What is a Friend Function? • A friend function is a non-member function that is granted access to the private and protected members of a class. • Declared using the keyword 'friend' inside the class.
- 4. Syntax • class ClassName { • friend returnType functionName(arguments); • }; • Declared inside the class with 'friend' keyword. • Defined outside the class like a regular function.
- 5. Example Code • class Box { • private: • int length; • public: • Box(int l) : length(l) {} • friend void printLength(Box b); • }; • void printLength(Box b) {
- 6. Key Points • Friend function is not a member of the class. • Can be declared in one or more classes. • Can be a normal function, a friend class, or an operator overload.
- 7. Use Cases • When two or more classes need to access each other's private data. • For operator overloading (especially <<, >>, +, etc.) • When a non-member needs special access privileges.
- 8. Friend Function vs Member Function • Aspect | Friend Function | Member Function • ----------------|----------------------|-------------------- ---- • Belongs to | Outside class | Inside class • Access private | Yes (if friend) | Yes • Called using | Object as argument | Object directly
- 9. Pros and Cons • Advantages: • • Increases flexibility • • Enables external helper functions • Disadvantages: • • Breaks encapsulation • • Reduces data hiding
- 10. Summary • Friend functions provide controlled access to private data. • Must be used sparingly to maintain encapsulation. • Useful for operator overloading and external utilities.
- 11. Questions? • Any doubts or clarifications?