On PHPMaster.com today there's a new tutorial posted, the first part of a series, looking at the use of the Standard PHP Library (SPL) in PHP. In this first part of the series, Stefan Froelich looks specifically at two of the more common uses for iterators - working with arrays and directories.

When I first came across the term iteration and saw the overwhelming list of classes related to it in the SPL, I was taken aback. It seemed maybe iteration was too complex for me to grasp. I soon realized it was just a fancy word for something we programmers do all the time. [...] In the first part of this two-part series I’ll introduce you to iteration and how you can take advantage of some of the built-in classes from the Standard PHP Library (SPL).

Included in the tutorial is example code showing how to use the ArrayIterator to work with an array and the DirectoryIterator to process the contents of a directory. He also briefly touches on a few other iterators like "FileExtensionFilter", "RecursiveDirectoryIterator" and "RecursiveArrayIterator".