Comments on: A JScript/VBScript Regex Lookahead Bug

By: mays

mays — Thu, 17 Dec 2009 13:43:07 +0000

@Craig : that i guess is because of .* wildcard in (?=.*\d)

Try this
/(?=^[a-zA-Z0-9]{6,20}$)(?=.+\d).+/

By: Regular expressions and the ASP.NET RegularExpressionValidator control â€“ an overview of useful links

Thu, 10 Sep 2009 13:12:49 +0000

[...] JScript/VBScript bug that is also present in Internet Explorer (almost any version): A JScript/VBScript Regex Lookahead Bug [...]

By: Craig

Craig — Tue, 09 Jun 2009 13:00:37 +0000

ok, my fix didn;t work as it now allows non alphanumeric chars!!!! I’m not sure how something so presumably simple is beginning to turn in an absolute nightmare!!!!!! validate password cross browser simple ? You’d think !

By: Craig

Craig — Tue, 09 Jun 2009 12:29:06 +0000

Not sure how relevant this is, but came across an odd issue in IE just now. My validation expression ^(?=.*\d)[a-zA-Z0-9]{6,20}$ worked in FF 3 (didn’t test other browsers except IE 7 where it kept *not* matching “valid” entries.
I changed the curly bracket part specifying the range to (?=.{6,20}) and it worked. Weird? or not? It always worked in FF 3 whichever way but IE only accepted the second way… Don’t have time right now to test other browsers but will revisit this later to test in other browsers as well – unless someone here has the time

By: Michael Ash's Regex Blog : Looking again at the Lookahead bug

Michael Ash's Regex Blog : Looking again at the Lookahead bug — Sat, 21 Feb 2009 19:39:05 +0000

[...] Levithan looked much closer at the problem in general and discussed it on his blog. He came to the conclusion that the qualifiers with a minimum boundary of zero, within the [...]