So how can you practice using regex if you are limited to just using them in your code? The answer is to use a utility, of which there are many, that uses regex for performing search and replace. I'm sure everyone is familiar with the standard "find x and replace it with y" type of search and replace. Most IDEs and text editors have built in regex engines to handle search and replace. In this article I'd like to walk through a series of exercises to help you practice using regex.

His examples are based on Netbeans but can be used in just about any IDE that supports regex (or even just your code). He shows how to match word boundaries, do some grouping, work with back references and doing some search/replace based on multiple groupings.

As the saying goes, "Just because you can do something doesn't mean you should." But in the world of programming, stretching boundaries is just part of the fun. The PHP community has never been one to shy away from bending their favorite language more ways than a shopping mall pretzel, and as the ten wild projects introduced in this article indicate, the fervor for experimentation is as strong as ever!

Here's their list of the ten projects they see as trying to stretch the language to its limits:

• LisPHP
• Phalanger
• PHPLinq
• PHP-GTK
• Quercus
• PHP.js
• Qwench
• Phergie