As we know, a method usually invokes another method. A method can also invoke itself. Such a method is known as recursive method.

A local class is declared locally within a block of Java code rather than as a member of a class Only classes may be defined locally: interfaces, enumerated types, and annotation types must be top-level or static member types. Typically, a local class is defined within a method, but it can also be defined within a static initializer or instance initializer of a class.

A class for which we cannot create objects is called an abstract class. A abstract class is to be extended and then instantiated.

Some of the methods in an abstract class may be declared as abstract methods. Such an abstract method consists of a declaration without any body, as shown below:

             abstract class test11
             {
             abstract int numtest();
             
             }         

A static variable is associated with the whole class instead of a specific instances of a class. But a Nonstatic variables take on unique values with each object instance.

Swing components are divided into three categories .There are Container components, Ordinary components, Menu components.