This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Can anyone say the difference between Instance block and constructor.....they bothr use to intialize .....see the following code
By "instance block" I presume you mean "instance initializer". A constructor can have parameters passed to it, and is probably a better way to initialise the values so as to establish the class invariant. Have look at the Java™ Language specification about initializers and constructors (1) and maybe (2).