Summary

This appendix showed you the basics of regular expressions—what they're used for, how to use the most common regular expression features, and the need to be aware of the differences between various regex flavors. Regular expressions are a very powerful tool, and I urge you to learn as much about them as you can—the investment in time will pay itself back many times over as you will be able to quickly solve problems using regexes that would take a lot of hard work to solve in other ways. Many interesting features of regular expressions such as look-ahead and look-behind matching, mode modifiers, and possessive quantifiers have not been covered here, but those are definitely things you'd want to read about if you get a book on regular expressions.