Re: regular expression

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On Tue, 2010-06-01 at 16:35 +0100, Richard Quadling wrote:

> On 1 June 2010 16:33, Ashley Sheridan <ash@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Tue, 2010-06-01 at 16:31 +0100, Richard Quadling wrote:
> >
> > $re1 = '/^[a-z]++$/i';
> > $re2 = '/^[a-z ]++$/i';
> >
> >
> >
> > --
> > -----
> > Richard Quadling
> > "Standing on the shoulders of some very clever giants!"
> > EE : http://www.experts-exchange.com/M_248814.html
> > EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp
> > Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
> > ZOPA : http://uk.zopa.com/member/RQuadling
> >
> >
> > Why the double ++ in the expressions there? Surely one + would match the 1 or more characters that you need and the second one would just be surplus?
> >
> > Thanks,
> > Ash
> > http://www.ashleysheridan.co.uk
> >
> >
> 
> ++ doesn't give back. As there is no need to do any backtracking, this
> is supposed to be a slight optimization.
> 
> 
> 
> --
> -----
> Richard Quadling
> "Standing on the shoulders of some very clever giants!"
> EE : http://www.experts-exchange.com/M_248814.html
> EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp
> Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
> ZOPA : http://uk.zopa.com/member/RQuadling


Ah, I ought to have guessed as it's you! ;)

I didn't know about that in regex's, I've learnt something new today!

Thanks,
Ash
http://www.ashleysheridan.co.uk



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