ansaurus

Question

Answer 1

+15 A:

Make it optional (match exactly one or zero times)

^([a-zA-Z0-9]{5,10})?$

SchlaWiener 2010-10-26 08:43:44

Thanks, your idea works and the explanation easy to understand.

MISS_DUKE 2010-10-26 10:47:06

No prob, btw. the ? quantifier is just a shortcut for {0,1}

SchlaWiener 2010-10-27 06:43:12

Answer 2

+3 A:

^(?:[a-zA-Z0-9]{5,10}|)$

joni 2010-10-26 08:44:09

SchlaWieners is the more elegant solution..

joni 2010-10-26 09:41:34

Thanks, your idea seems working, but I do not understand it.

MISS_DUKE 2010-10-26 10:47:51

You see the pipe "|" nearly at the end of the regex? It's like an OR operator, in this case ` [a-zA-Z0-9]{5,10} ` OR "" :)

joni 2010-10-26 11:09:32

Regex question ^[a-zA-Z0-9]{5,10}$