What is nested class in OOP?

In object-oriented programming (OOP), an inner class or nested class is a class declared entirely within the body of another class or interface . It is distinguished from a subclass.

A nested class is a class that is declared in another class . The nested class is also a member variable of the enclosing class and has the same access rights as the other members. However, the member functions of the enclosing class have no special access to the members of a nested class.

A nested class is a member and as such has the same access rights as any other member . The members of an enclosing class have no special access to members of a nested class; the usual access rules shall be obeyed. For example, program 1 compiles without any error and program 2 fails in compilation.