return NULL by reference

21 years ago by Jeffrey Moss — view source — reply

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I can't seem to reproduce this bug, I was wondering if anyone has any input they could give me....

I wrote a function to return a parameter by reference that worked with PHP5.0 RC1, looks like this:

function & getParameter ($name)
{
if (isset($this->params[$name]))
{
return $this->params[$name];
}
return NULL;
}

Now I recently upgraded to PHP5.0.2 and I get errors. I have tried to make a test case script to demonstrate it but it works fine in command line. My cgi script is huge, so I can't tell you how to reproduce it, but it's giving me this error: "Only variable references should be returned by reference " on the line with "return NULL;".

Could this be related to another bug? The code works fine if I replace "return NULL" with anything else, even "return $nonexistant->variable;". Is there a way I can turn this check off?

-Jeff Moss

21 years ago by Daniel Convissor — view source — reply

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    return NULL;

... snip ...

"Only variable references should be returned by reference "

Just like the error message says. "References" are referring to
variables. NULL isn't a variable. Do this instead:

      $tmp = null;
      return $tmp;

--Dan

--
T H E A N A L Y S I S A N D S O L U T I O N S C O M P A N Y
data intensive web and database programming
http://www.AnalysisAndSolutions.com/
4015 7th Ave #4, Brooklyn NY 11232 v: 718-854-0335 f: 718-854-0409

21 years ago by Jeffrey Moss — view source — reply

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Well I can't reliably reproduce it, is this expected behavior or not? If
there is a cleaner solution I'd like to try that first.

I'd like to turn off this error altogether even if I have to patch and
recompile. I can't see anything like this in the changelogs. Since when
should anything not be allowed to return null?

-Jeff

----- Original Message -----
From: "Daniel Convissor" danielc@analysisandsolutions.com
To: "Jeffrey Moss" jeff@opendbms.com
Cc: internals@lists.php.net
Sent: Monday, September 27, 2004 12:04 PM
Subject: Re: [PHP-DEV] return NULL by reference

    return NULL;
... snip ...

"Only variable references should be returned by reference "

Just like the error message says. "References" are referring to
variables. NULL isn't a variable. Do this instead:
      $tmp = null;
      return $tmp;
--Dan

--
T H E A N A L Y S I S A N D S O L U T I O N S C O M P A N Y
data intensive web and database programming
http://www.AnalysisAndSolutions.com/
4015 7th Ave #4, Brooklyn NY 11232 v: 718-854-0335 f: 718-854-0409

21 years ago by Lukas Smith — view source — reply

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Daniel Convissor wrote:

   return NULL; 
... snip ...

"Only variable references should be returned by reference "

Just like the error message says. "References" are referring to
variables. NULL isn't a variable. Do this instead:
      $tmp = null;
      return $tmp;

i thought that one was fixed?

regards,
Lukas

21 years ago by Derick Rethans — view source — reply

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    return NULL;
... snip ...

"Only variable references should be returned by reference "

Just like the error message says. "References" are referring to
variables. NULL isn't a variable. Do this instead:
      $tmp = null;
      return $tmp;

Although this is a totally stupid thing to do.

Derick