DevShed has posted the second and last part of a series of two articles based around the Composite design pattern - using it to work with strings in PHP5.

Are you a PHP developer who wants to improve your skills in pattern-based programming in PHP? If the answer to this question is a emphatic yes, then you should begin reading this article now! Welcome to the final part of the series "Implementing the composite pattern with PHP 5." Comprised of two instructive tutorials, this series walks you through the basic concepts of this important design pattern, and shows you how to apply it with some educational examples.

They start by defining a simple StringProcessor class as an abstract interface to build from. From there, they create two other classes - the SingleStringProcessor and the MultipleStringProcessor. Each of these takes in either a single file or multiple filenames and spits back out the value of the string and the length of the string.