A Crash-Course in Regular Expressions
Hi everyone. I originally released this screencast back when this blog only had about two hundred subscribers. Lately, many of our new readers have been asking me about using regular expressions. So, I decided to bump this one back to the top. I hope you enjoy it!
To a novice web developer, regular expressions look like the most scary thing on the planet. Who could possibly dismantle such a block of code and decipher its meaning? Luckily, its bark is much worse than its bite. You’ll quickly find that regular expressions are rather straight-forward and easy to understand – once you learn the syntax.
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Additional Resources
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Regular Expressions Cheat Sheets
Whether you’re searching strings or validating input fields, the use of regular expressions will save you a great deal of time. I found a great cheat sheet from AddedBytes.com that should save you a great deal of time. It’s a free PDF download, so get to it!
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Using Regular Expressions with PHP
This site specializes in all things related to “regular expressions”. It should be your first stop on your learning question.
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PHP Regular Expression Tutorial
Regular expressions are a powerful tool for examining and modifying text. Regular expressions themselves, with a general pattern notation almost like a mini programming language, allow you to describe and parse text. They enable you to search for patterns within a string, extracting matches flexibly and precisely.
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Using Regular Expressions with PHP
In this article I will show you how to use PHP regular expressions in your own PHP scripts.
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Comments
Jeffrey
Hi, I'm Jeff. I'm the editor of Nettuts+, and the Site Manager of Theme Forest. I spend too much time in front of the computer and find myself telling my fiance', "We'll go in 5 minutes!" far too often. I just can't go out to dinner while I'm still producing FireBug errors...drives me crazy. I love jQuery, PHP, MYSQL, CSS, AJAX - pretty much anything.
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Bad choice in pictures for open
Nice tutorial, thanks
thanks for the nice tut, explained everything
at the part where the regex for email addreses is done there a missing $ sign at the end,…
so it not only will valitate “sitemanager@themeforest.net” but also “sitemanager@themeforest.net something else here” ??
here some examples which would be valid email addresses but invalid acording to the used regex,…
email@some-site.com
email@blog.somesite.com
email@somesite.co.uk (same ideea as above)
i think this would be a better regex for emails,.. please correct me if im wrong
\^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$\
Nice!
Jeff, I really love your screencasts, you’re really good at explaining things!
Keep up the good work
Another excellent video tutorial clearing up my confusion over Regular Expressions. I have “Mastering Regular Expressions” by Friedel and got lost somewhere in there. You have opened another door for me. Thanks
It is such a relief to have discovered your tutorials which do improve my learning curve drastically
Outdated tutorial.
Another great eye opener.
Thank you very much.
Thanks Jeffrey, I was making a contact form today and this came in handy.
\^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$\
^^
this would work but you forgot to close scope the .***
so:
/^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.{[a-zA-Z],{2,4}}$\