Re: regular expression

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

-- 
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php



[Index of Archives]     [PHP Home]     [Apache Users]     [PHP on Windows]     [Kernel Newbies]     [PHP Install]     [PHP Classes]     [Pear]     [Postgresql]     [Postgresql PHP]     [PHP on Windows]     [PHP Database Programming]     [PHP SOAP]

  Powered by Linux