What is Class in Java Programming language and OOPS Tutorial Example

See http://javarevisited.blogspot.sg/2011/10/class-in-java-programming-general.html for more details on What is Class in Java. By the way Class in Java or Object oriented programming language is one of the most important concept to understand. For simplicity you can refer class as user defined data type which allows to model any real world entity. Class is a blueprint which is used to create object e.g. Person class can represent all persons in world. Another way of looking Class as combining variables and methods together. method operates on those variable which is used to keep state of Object. Few important things about Class in Java : 1) Class is created using class keyword in Java. 2) There are two kinds of class top level class and Inner class. Any class which is not declared inside another class is called top level class while a class which is nested inside another class is known as nested or Inner class in Java. 3) As per Java coding convention Class starts with capital letter e.g. Helloworld, String etc. Related tutorials and examples : http://javarevisited.blogspot.sg/2012/12/what-is-object-in-java-or-oops-example.html http://javarevisited.blogspot.sg/2012/12/inner-class-and-nested-static-class-in-java-difference.html http://java67.blogspot.sg/2012/10/nested-class-java-static-vs-non-static-inner.html