Friend class: – It is also possible to make an entire class as friend class to access the private member another class.

As we know that friend is not sharable so suppose we have two classes class A and class B. if class A is friend of class B then class B will not be a friend of class A.

Local class: – When a class is created inside any function then class is called as local class. This class can have all the feature as normal class.

Nested class: – When a class is created inside public section of another class then the class is called as inner or nested class.

Syntax: – To access the nested class

                Outer_Class_Name::Nested_Class_Name Object_Name;

Constant member function: – When we suffix const keyword with any member function with class then that member function called as constant member function. Inside constant member function we cannot perform any special operation. Like modification of data. To process the constant data, only CPU resister are use.

Recursive member function: – A member function can also be recursive. Recursive member function calls to itself for number of times based upon condition is true.