RE: [PHP] OT - Regular Expression
| From: | Edward Kay | Date: | Fri, 09 Feb 2007 15:16:37 +0000 |
| Subject: | RE: [PHP] OT - Regular Expression | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-248653@lists.php.net to get a copy of this message | ||
> > As Rob suggested, why not just use two checks? e.g.
> >
> > if ( (strlen($input) == 4) && (strpos($input, '8') !== FALSE ) ) {
> > // OK
> > } else {
> > // Not OK
> > }
> >
> > Not only is this logic much easier to understand than a regexp
> - important
> > when someone else has to maintain your code later on etc., I
> also believe it
> > will be faster than using preg_match.
>
> Those would be the wrong two checks, you'd need 3 checks to do it that
> way, I still suggested using a regex. The reason being that the original
> requirements need the entire input to be digits :)
>
> <?php
>
> if( ereg( '^[[:digit:]]{4}$', $input )
> &&
> strpos( $input, '8' ) )
> {
> // woot!
> }
>
> // Or alternatively...
>
> if( strlen( $input ) == 4
> &&
> strpos( $input, '8' )
> &&
> ctype_digit( $input ) )
> {
> // woot!
> }
>
> ?>
>
> Cheers,
> Rob.
Oops - good catch!
You still need the !== FALSE test with strpos through. Without it, the test
will fail for any string starting with 8 as strpos will return 0.
Edward