RE: [PHP] strpos mystery
On 29 July 2004 01:50, Jon Drukman wrote:
> with this code fragment:
>
>
> $string='/mobile/phone.html';
> if (strpos($string,'/mobile/')!==false) { print "one: yes\n"; }
> if (strpos($string,'/mobile/')===true) { print "two: yes\n"; }
>
> >
>
>
> only the first if statement prints anything. why is !==
> false not the
> same as === true ?
Because strpos returns the integer offset of the found substring, or FALSE
if not found; it *never* returns TRUE. (You need the !== test because
strpos() can return an offset of zero, which would be ==FALSE but not
===FALSE.)
Cheers!
Mike
-
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Learning Support Services, Learning & Information Services,
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Headingley Campus, LEEDS, LS6 3QS, United Kingdom
Email: [EMAIL PROTECTED]
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Re: [PHP] strpos mystery
Heck, even I got it wrong ;) True check below should always fail...
Jason Barnett wrote:
Because === and !== check the type as well. Of you set $string =
'blah' you'll still get the same result.
If you were using != and == both would print.
strpos() returns an int, so comparing it to false with === is always
false. The same would be true for true.
That's half right. strpos actually *can* return false as opposed to 0,
so checking doing the === check might be necessary for your application.
$string = 'blah';
if (strpos($string, 'not in the original $string') === false){
echo 'False check succeeded - not in $string.';
}
if (strpos($string, $string) === true) {
echo 'True check succeeded - in string';
} else {
echo 'True check failed - because strpos was at offset 0.';
}
?>
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Re: [PHP] strpos mystery
Because === and !== check the type as well. Of you set $string =
'blah' you'll still get the same result.
If you were using != and == both would print.
strpos() returns an int, so comparing it to false with === is always
false. The same would be true for true.
That's half right. strpos actually *can* return false as opposed to 0, so
checking doing the === check might be necessary for your application.
$string = 'blah';
if (strpos($string, 'not in the original $string') === false){
echo 'False check succeeded - not in $string.';
}
if (strpos($string, $string) === true) {
echo 'True check succeeded - in string';
} else {
echo 'True check failed - because strpos was at offset 0.';
}
?>
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Re: [PHP] strpos mystery
On Wed, 28 Jul 2004 17:50:01 -0700, Jon Drukman <[EMAIL PROTECTED]> wrote:
> with this code fragment:
>
>
> $string='/mobile/phone.html';
> if (strpos($string,'/mobile/')!==false) { print "one: yes\n"; }
> if (strpos($string,'/mobile/')===true) { print "two: yes\n"; }
>
> ?>
>
> only the first if statement prints anything. why is !== false not the
> same as === true ?
Because === and !== check the type as well. Of you set $string =
'blah' you'll still get the same result.
If you were using != and == both would print.
strpos() returns an int, so comparing it to false with === is always
false. The same would be true for true.
>
> -jsd-
>
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> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
> !DSPAM:410846c1241919501214933!
>
>
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