Regex (?(expression) yes|no) How to use this?

[Edu]

Hi ,
I need an exemple of how to use these following 2 Alternation Construncs:

(?(expression)yes|no)
(?(name)yes|no)

Source:
http://msdn.microsoft.com/library/d.../cpgenref/html/cpconalternationconstructs.asp

I'm trying to understand how to use them but no luck so far. An exemple may
help me out.

Thanks,
Edu

 

[Dino Chiesa [MSFT]]

Regular Expressions are a language in themselves, and the syntax can be
daunting, at first. For anyone who is using Regex in the .NET Framework, I
always recommend getting one of the visual Regex tester tools.

- Regex Designer - by Chris Sells
http://www.gotdotnet.com/Community/Workspaces/Workspace.aspx?id=01e0dfb7-0182-45cd-94f7-2ed2df2504a9
check out this picture of the UI:
http://www.sellsbrothers.com/tools/index.1.jpg

- RegEx, by Gerry Shaw
http://www.organicbit.com/regex/fog0000000019.html

Both of the above include source code, for those who are interested. They
are
primarily useful as tools to build and test regex's that you can then
include into
apps.


-Dino