Learn regular expressions in about 55 minutes
The tutorial I learned regular expressions from, which is longer but more detailed than this one, was <a href="http://www.regular-expressions.info/" rel="nofollow">http://www.regular-expressions.info/</a>. It’s free, thorough and well-organized. Its only flaw is that its section on support in various languages is out of date. It was written to sell a Windows-only regex tool, but it’s very non-pushy with the advertisements.<p>You can see a list of online regular expression testers for various languages at the Stack Overflow “regex” tag wiki, in the “Online sandboxes” section: <a href="http://stackoverflow.com/tags/regex/info" rel="nofollow">http://stackoverflow.com/tags/regex/info</a>. For JavaScript regexes, <a href="http://regexpal.com/" rel="nofollow">http://regexpal.com/</a> is easy to use.