Define access modes within a class. How can we access the class member? list out the characteristics of friend function.

 Access modes, also known as access specifiers, are used in C++ to control the access to class members. There are three access modes in C++: public, private, and protected.

1. Public access mode: Members declared as public can be accessed by any code that has access to the object of the class
2. Private access mode: Members declared as private can only be accessed by member functions of that class.
3. Protected access mode: Members declared as protected can be accessed by member functions of that class and by member functions of any derived class

Access to class members can be obtained through objects of the class. For example, to access a public member variable of a class MyClass, we can create an object of the class and use the dot operator to access the member variable:

MyClass obj;

obj.publicVar = 10;   // accessing public member variable of MyClass

A friend function in C++ is an non-member function that has access to the private and protected members of a class. It is declared inside the class with the keywork "friend".

Characteristics of a friend function:

1. A friend function is not a member function of the class.
2. It can be declared in any section of the class(public, private or protected).
3. It has the ability to access the private and protected members of the class.
4. It is invoked like a regular function, not through an object.
5. It can be declared outside the class or  defined within the class.