Wrapping up their series on Iterators in PHP, DevShed has posted Traversing Data Structures in PHP 5 - a look a combining embedded classes with the SPL to work through your data.

Welcome to the final part of the series "Iterators in the Simplest Sense." In this set of articles, you'll learn the basic concepts of iterators in PHP 4 and PHP 5. The overall learning experience is strongly focused on the practical sense of the topic, so you can start quickly using iterators within your own PHP applications.

In this last article I'll explore the implementation of PHP 5 iterators, by utilizing some of the embedded classes that integrate the powerful SPL package. Thus you can learn quickly how to include these programming structures inside your PHP applications.

They jump right in and start working with the SPL functions to create a simple, readable iterator class ("FileIterator"). They follow this with two examples building on the class - one that works with data from a text file, and the other from a MySQL database.