In Java 1.0 and 1.1, the two primary collection classes were Vector and Hashtable, and the Iterator design pattern was implemented in a class called Enumeration.

All the classes released in Java 2 that implement the collection interface contain an iterator () method, which returns an instance of the Iterator. There's nearly universal support for the Iterator ...

The Java Iterator is accessible to all Collection classes, but the ListIterator is confined only to classes that implement the List interface.

The Java 2 SDK organizes its vast collection of classes and interfaces into a tree-like hierarchy of packages within packages, which is equivalent to directories within directories.

This post explains how to use classes in Java to build objects and organize your code. Also learn: constructors, static methods, and more!