Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Learn the difference between classes and interfaces once and for all, then get started declaring, implementing, and extending interfaces in your Java programs ...

Learn how to create and use an interface in C, which is a way of defining a set of functions that a struct must implement to achieve polymorphism.

Anyway- its an implementation of a Trie following these interfaces.. It seems to work okay, but I'm not sure how to go about coding the iterator..