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PHP 5.0.3 E_STRICT question - returning NULL from reference returning function

php.internals

Yermo Lamers

21 years ago

What is the proper way to return a NULL condition from a method that
returns a reference?

function &testfunc()
{
return NULL;
}

generates:

"Strict Standards: Only variable references should be returned by
reference in ..."

Is the correct approach to do something like:

function &testfunc()
{
$nullVar = NULL;
return $nullVar;
}

??

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Zeev Suraski

21 years ago

At 06:47 06/03/2005, Yermo Lamers wrote:

>What is the proper way to return a NULL condition from a method that
>returns a reference?
>
>function &testfunc()
>{
>return NULL;
>}
>
>generates:
>
>"Strict Standards: Only variable references should be returned by
>reference in ..."
>
>Is the correct approach to do something like:
>
>function &testfunc()
>{
>$nullVar = NULL;
>return $nullVar;
>}

That'd work, yep.

Zeev

npguy

21 years ago

Just curious what is the techincal aspect of the such case. Why need NULL
identifier for the return not NULL iteself.

----- Original Message -----
From: "Zeev Suraski" <zeev@zend.com>
To: <yml@dtlink.com>
Cc: <internals@lists.php.net>
Sent: Sunday, March 06, 2005 10:36 AM
Subject: Re: [PHP-DEV] PHP 5.0.3 E_STRICT question - returning NULLfrom
reference returning function

Derick Rethans

21 years ago

On Sun, 6 Mar 2005, Zeev Suraski wrote:

> At 06:47 06/03/2005, Yermo Lamers wrote:
>
> >What is the proper way to return a NULL condition from a method that
> >returns a reference?
> >
> >function &testfunc()
> >{
> >return NULL;
> >}
> >
> >generates:
> >
> >"Strict Standards: Only variable references should be returned by
> >reference in ..."
> >
> >Is the correct approach to do something like:
> >
> >function &testfunc()
> >{
> >$nullVar = NULL;
> >return $nullVar;
> >}
>
> That'd work, yep.

Wrong ;-) It causes problems with reference counting - and will segfault
PHP after some time.

Derick

--
Derick Rethans
http://derickrethans.nl | http://ez.no | http://xdebug.org

Yermo Lamers

21 years ago

>> >Is the correct approach to do something like:
>> >
>> >function &testfunc()
>> >{
>> >$nullVar = NULL;
>> >return $nullVar;
>> >}
>>
>> That'd work, yep.
>
> Wrong ;-) It causes problems with reference counting - and will segfault
> PHP after some time.
>
> Derick

Then what is the correct approach to handling this?

-- Yermo

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Zeev Suraski

21 years ago

At 17:06 06/03/2005, Derick Rethans wrote:

>On Sun, 6 Mar 2005, Zeev Suraski wrote:
>
> > At 06:47 06/03/2005, Yermo Lamers wrote:
> >
> > >What is the proper way to return a NULL condition from a method that
> > >returns a reference?
> > >
> > >function &testfunc()
> > >{
> > >return NULL;
> > >}
> > >
> > >generates:
> > >
> > >"Strict Standards: Only variable references should be returned by
> > >reference in ..."
> > >
> > >Is the correct approach to do something like:
> > >
> > >function &testfunc()
> > >{
> > >$nullVar = NULL;
> > >return $nullVar;
> > >}
> >
> > That'd work, yep.
>
>Wrong ;-) It causes problems with reference counting - and will segfault
>PHP after some time.

Hmm, that in itself shouldn't cause any problems unless it's coupled with
something else that's causing problems...  Not that it helps you any if you
end up bumping into problems :)

Zeev

Yermo Lamers

21 years ago

>> > >function &testfunc()
>> > >{
>> > >$nullVar = NULL;
>> > >return $nullVar;
>> > >}
>> >
>> > That'd work, yep.
>>
>>Wrong ;-) It causes problems with reference counting - and will segfault
>>PHP after some time.
>
> Hmm, that in itself shouldn't cause any problems unless it's coupled with
> something else that's causing problems...  Not that it helps you any if
> you end up bumping into problems :)

True; but it's good to know what the "correct" thing to do is; even if
there is an underlying bug.

-- Yermo

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