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Compose and analyze regex patterns with RegexBuddy's easy-to-grasp regex blocks and intuitive regex tree, instead of or in combination with the traditional regex syntax. Developed by the author of this website, RegexBuddy makes learning and using regular expressions easier than ever. Get your own copy of RegexBuddy now
BETA--NOT YET UPDATED FOR REGEXBUDDY 4
If you have worked through the entire tutorial, I guess you will agree that regular expressions can quickly become rather cryptic. Therefore, many modern regex flavors allow you to insert comments into regexes. The syntax is (?#comment) where "comment" can be whatever you want, as long as it does not contain a closing parenthesis. The regex engine ignores everything after the (?# until the first closing parenthesis.
E.g. I could clarify the regex to match a valid date by writing it as (?#year)(19|20)\d\d[- /.](?#month)(0[1-9]|1)[- /.](?#day)(0[1-9]|[0-9]|3). Now it is instantly obvious that this regex matches a date in yyyy-mm-dd format. Some software, such as RegexBuddy, EditPad Pro and PowerGREP can apply syntax coloring to regular expressions while you write them. That makes the comments really stand out, enabling the right comment in the right spot to make a complex regular expression much easier to understand.
To make your regular expression even more readable, you can turn on free-spacing mode. All flavors that support comments also support free-spacing mode. In addition, Java supports free-spacing mode, even though it doesn't support (?#)-style comments.
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Page URL: http://www.regex.asia/comments.html
Page last updated: 15 July 2013
Site last updated: 03 March 2014
Copyright © 2003-2013 Jan Goyvaerts. All rights reserved.
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|Shorthand Character Classes|
|Grouping & Capturing|
|Backreferences, part 2|
|Lookahead & Lookbehind|
|Lookaround, part 2|
|XML Character Classes|
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