4 Replies Latest reply on Jun 30, 2008 6:04 AM by LDJessee

    Regular Expression Help


      I am trying to validate an input field using Regular Expression. I have gotten regexp to work great for me in the past, including things like dates, email addresses and such, but this one is kicking my butt.

      From what I have read, this pattern should work:


      (4 or 5 characters, with the middle 1-6 optional)

      This should match items like:

      And should not match:

      I thought the question mark made the previous character optional (match 0 or 1 time).

      If I take the ? out, then I can get PA3IT to work and PA9IT does not, but neither does PACH or SS0F.

      Any suggestions?

      Doug Jessee
      (At CFUnited 2008 I learned too much, now I have to change everything.)
        • 1. Re: Regular Expression Help
          BKBK Adobe Community Professional & MVP
          ... should not match:

          It doesn't. It matches PA9I and PAIT, but not PA9IT or PAIT9.

          It also matches PA3IT, PACH and SS0F, as you require.

          • 2. Re: Regular Expression Help
            BKBK Adobe Community Professional & MVP
            Did you once use {2,3} in place of {2,2}? Just a thought.

            • 3. Re: Regular Expression Help
              LDJessee Level 1
              Hello and thanks for responding.

              I did not use {2,3}.

              What I am trying to get to work is a Regular Expression that matches the items in 'should' and not match the 'should not'.

              I have tried several variations, but from what I have read, the regular expression I included should match those patterns. In actual usage, it does not, atleast not in ColdFusion v7.0.2.

              The regular expression I included will correctly match things like PA3IT, but will also match things I dont want it to, like PA9IT. It also does not match things like SS0F.

              I say it does or does not work from actually trying it on a coldfusion server.

              Any help or suggestions as to changing the regular expression would be greatly appreciated.

              • 4. Re: Regular Expression Help
                LDJessee Level 1
                A former coworker figured it out.

                I simply needed to put boundaries at the beginning and end.


                By simply adding the carrot (^) and dollar sign ($), it works as expected.