13 Regular Expressions
If there were just two things you should understand about regular expressions, they would be that regular expressions are supremely useful in advanced programming and that they’re easy to use but taxing to write. However, once you understand the rules for writing regular expressions, that extra knowledge will pay off in spades because regular expressions can vastly improve the quality of your programming.
This chapter will identify what regular expressions are, discuss the rules for constructing them (in great detail), and provide some useful examples demonstrating their capabilities.
Important Compatibility Note
Most of the book has been updated for PHP 6, while still being backward compatible for older versions. ...