Is nested class allowed in Java?

There are basically four types of inner classes in java.

In Java, just like methods, variables of a class too can have another class as its member. Writing a class within another is allowed in Java . The class written within is called the nested class, and the class that holds the inner class is called the outer class. Following is the syntax to write a nested class.

A nested class is a member of its enclosing class . Non-static nested classes (inner classes) have access to other members of the enclosing class, even if they are declared private. Static nested classes do not have access to other members of the enclosing class.