This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Actually, it will return to you a reference of some class that implements the Enumeration interface. This interface guarantees that whatever class it is, it implements the methods hasMoreElements() and next().
This is the power of programming to an interface. If someone comes up with the super data structure where everything is implemented in the best way possible, the designers of the Vector class can replace what they are using now and return the super data structure, and as long as it also implements Enumeration, it won't break your code.
A bit of business: you may not have read our naming policy on the way in. It requires that you use a full, real (sounding) first and last name for your display name. Initials aren't enough. You can change your display name here. Thanks!