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Static Nested Classes

• As with class methods and variables, a static nested class is associated with its outer class. And like static class methods, a static nested class cannot refer directly to instance variables or methods defined in its enclosing class: it can use them only through an object reference

• Note: A static nested class interacts with the instance members of its outer class (and other classes) just like any other top-level class. In effect, a static nested class is behaviorally a top-level class that has been nested in another top-level class for packaging convenience.

• Static nested classes are accessed using the enclosing class name:

OuterClass.StaticNestedClass

• For example, to create an object for the static nested class, use this syntax:

OuterClass.StaticNestedClass nestedObject =
     new OuterClass.StaticNestedClass();

• An instance of an inner class cannot be created without an instance of the outer class. Therefore, an inner class instance can access all of the members of its outer class, without using a reference to the outer class instance. For this reason inner classes can help make programs simple and concise.

• A static nested class may be instantiated without instantiating its outer class. Inner classes can access both static and non-static members of the outer class. A static class can access only the static members of the outer class.