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Regular Expression Evaluator


Regular expressions are a very powerful tool for handling strings. They are widely used by developers in Java, .NET, PHP, etc. If you are new to regular expressions you can learn from several tutorials (e.g. http://java.sun.com/docs/books/tutorial/extra/regex/intro.html [1], http://www.regular-expressions.info/tutorial.html [2]or http://mindprod.com/jgloss/regex.html [3]). However, learning is much more efficient with interactive hands-on experience. The excellent tutorial at Sun [1], provides a simple test harness that allows a reader to try the covered material. However, if you are working with regular expressions on a regular basis you might desire a tool that would accurately and quickly evaluate a variety of complex constructs. Great News: The RegexEvaluator! The utility currently handles the Java flavor of regular expressions. I plan to add other flavors when need arrives (C#, Perl, Python and PHP.) The latest source is available for download here.


I believe that the utility is quite self-explanatory and therefore not much help is provided. Just one minor explanation of the “instant evaluation” mode. When you check the “Instant” check box all of the “Find” push buttons will change to toggle buttons with “Find” button pushed by default. Once enabled, the evaluator listens to any changes in both “Regular Expression” and “Source Text” text areas. It means that when you type or delete a character, the application immediately compiles the regular expression, matches the input and displays results.

Applet Version

The RegexEvaluator applet will appear below in a Java enabled browser.

Java Web Start Version

If you desire faster response or off-line application you can run RegexEvaluator as a java web start application.

Future Enhancement


If you have any suggestions or bug report send them to: martin@askitservices.com