[PHP-DOC] #19699 [Com]: 'array_walk()' violates recommended 'allow_call_time_pass_reference=Off' From: tater <email protected>
Date: 11/26/02

 ID: 19699
 Comment by: tater <email protected>
 Reported By: fvu <email protected>
 Status: Open
 Bug Type: Documentation problem
 Operating System: Windows
 PHP Version: 4.2.3,4.3.0-dev
 New Comment:

Why not just add a flag parameter to array_walk() saying that the
userdata param should be a reference?

If "future versions may not support this any longer", there will be no
way for array_walk to modify external variables, and that's a serious
BC problem.

Previous Comments:
------------------------------------------------------------------------

[2002-10-04 03:04:31] fvu <email protected>

James,

indeed your example would break existing code if '$userdata' would
*always* be passed by reference.

I think the solution would be to let array_walk pass '$userdata' by
reference only if specified so in 'my_function' (just the same as the
first parameter behaves).

Your example would still work then since '$userdata' in my_function()
is specified without an ampersand, so it should be passed by value.

------------------------------------------------------------------------

[2002-10-03 19:38:55] sniper <email protected>

updated version information.

------------------------------------------------------------------------

[2002-10-03 16:27:08] jmoore <email protected>

OK.

Manual is incorrect here, in PHP4 functions either specify if an arg is
passed by ref or by value. In array_walk only the first argument is
ever passed by reference. I can see that passing userdata by reference
would be nice but unfortuantly it is too much of a big change that
could break too many scripts to make as this point as people may be
relying on the fact it is passed by reference.

For example

function my_function($value, $key, $userdata)
{
     $userdata = strrev($userdata.$key.$value);
}

$array1 = array("one", "two", "three")l
$mydata = "array1";
array_walk($array1, 'my_function', $mydata);

This POOR example would not work with thrid parameter passed by ref so
for now am changing this to a documentation problem as the
documentation is currently slightly misleading in it advocates using
calltime pass by reference when infact the first param only is ever
passed by reference.

- James

------------------------------------------------------------------------

[2002-10-03 15:50:01] fvu <email protected>

I tried using the latest snapshot for Windows:

   System Windows 9x localhost 4.10
   Build Date Oct 3 2002 20:15:03

but I still encounter the same problems.

------------------------------------------------------------------------

[2002-10-01 18:51:35] sniper <email protected>

Please try using this CVS snapshot:

  http://snaps.php.net/php4-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-latest.zip

------------------------------------------------------------------------

The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
    http://bugs.php.net/19699 

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Edit this bug report at http://bugs.php.net/?id=19699&edit=1

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