2007. 08. 10, péntek keltezéssel 02.31-kor Jan Reiter ezt írta:
> Hi!
> Thank you for your response!
>
> The only intention of my code was to investigate the (back then) unexpected
> behavior of the if statement.
>
>
> With $var['test'] set to "blah" this expression should be false
> ($var['test'] == 0) for what I know ...
>
> $var['test'] = "blah";
> var_dump($var['test'] == 0);
>
> //returns bool(true)
>
> Now I know why this happens! According to Table 6.5 of the Operators page in
> the PHP Manual in this comparison all of the values are converted to
> integer. And atoi("blah") for sure will fail!;-) So you have to use === to
> keep the types of the values!
I found something interesting:
znemeth@devguy3:~ php -r '$var = 'bla'; var_dump('0' == $var);'
bool(true)
znemeth@devguy3:~ php -r '$var = 'bla'; var_dump("0" == $var);'
bool(false)
version is 5.2.1
is this expected behaviour to be a difference between the two types of
quotes in this case?
greets
Zoltán Németh
>
> Jan
>
>
>
> -----Original Message-----
> From: Jim Lucas [mailto:lists@xxxxxxxxx]
> Sent: Friday, August 10, 2007 1:47 AM
> To: Jan Reiter
> Cc: pmcurry@xxxxxxxxx; php-general@xxxxxxxxxxxxx
> Subject: Re: I know this is not easy and I'm not stupid but...
>
> Jan Reiter wrote:
> > Hi!
> >
> > Phil:
> > Still I am curious what var_dump($userValues['afterDark']); at line 102.5
> > would return.
> > I managed to recreate that fault with
> >
> > $var['test'] = "blah";
> >
> > echo ($var['test']);
> >
> > if( $var['test'] == 0)
> > {
> > echo "ok";
> > }
> >
> > //this returns blahok -- not expected.
> >
> > In my case Var_dump() returns string(4) "blah" as expected.
> >
> > Using
> >
> > if( $var['test'] === 0)
> >
> > behaves as expected!!
>
> Are you wanting to only test for a empty/non-empty string?
>
> if so, use this.
>
> if ( empty($var['test']) ) {
> echo "var['test'] is empty";
> }
>
> >
> >
> > Jim:
> > TypeCasting would only be effective if you used the type sensitive
> > comparison operator === , because with "==" 0 equals NULL equals false
> > equals "" and so on ... or do I miss something here??
> >
> >
> > Hope that solves it for you! I'm still investigating why my first examples
> > fails. I've got the strong feeling that I'm missing something there. I
> don't
> > believe in a php bug or a memory leak in this case! Must be something
> pretty
> > obvious! Anyone a clue??
> >
> > Thanks,
> > Jan
> >
> >
>
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