Validating a string.

Giganews Newsgroups
Subject: Validating a string.
Posted by:  Adam David Moss (admoss@nospamglobalnet.co.uk)
Date: Sun, 20 Jul 2003

Hello,

I have a requirement whereby I must validate that a string matches one of
several patterns:

1.  An ISO standard 2 character country code (eg GB, NL) followed by five
digits.
2.  An ISO standard 2 character country code (eg GB, NL) followed by an X
followed by five digits.
3.  3 characters in the range a-z followed by 3 digits followed by 2
characters in a specific set (eg MT, AT, DA).
4.  4 characters followed by a hash (#) followed by 3 characters followed by
3 digits followed by a hash followed by 3 characters.
5.  4 characters followed by a hash (#) followed by 3 characters followed by
3 digits followed by a hash followed by 4 characters.

I have been told that a better way to achieve this than using .charAt is by
using something called a regular expression, but I don't really understand
them.  Can anyone please advise on the above or alternatively point me in
the direction of a suitable resource on these regular expression things?

Cheers,

Adam M.

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