Re: regular expression question

Matthew Lasar wrote: > At 11:32 AM 8/31/2007, Per Jessen wrote: >>Matthew Lasar wrote: >> >> > But I don't understand why the second half of the regular >> > expression works. I'm talking about this part: >> > >> > @([-a-z0-9]+\.)+[a-z]{2,}/"; >> > >> > why is it able to detect repeated sections of the email address >> > after "@" that are separated by periods? like "@email.alaska.com" >> > .. >> > It looks to me like it's only looking for one example of that >> > pattern. Does the "()" allow an unlimited number of patterns to >> > pass? >> >>No, but the following '+' does. > > But how? The +[a-z]{2,} seems to allow at least > two a-z clusters, but it doesn't include a period. /ml > That plus applies to the grouping () before it: ([-a-z0-9]+\.)+ one or more sequences of -a-z0-9 followed by a period /Per Jessen, Zürich