Creating a Class
		Building a program normally requires a number of classes. One must have the public static void main(String args[]) method, often simply called a main method.  This is the one that starts the entire program. Others need not have a main method, but often do for unit testing purposes. Nearly all classes have instance fields and methods.  I'd have a hard time thinking of a class that wouldn't. All classes require constructors. If you do not have a constructor or cannot afford one, Java will provide one for you. This is called the default constructor, it takes no arguments (parameters). You can have parameters in a constructor if you specify them.  If you do this, or if you simply make one without parameters, Java will not create the default constructor.