ID:               19699
 Updated by:       [EMAIL PROTECTED]
 Reported By:      fvu at wanadoo dot nl
-Status:           Open
+Status:           Bogus
 Bug Type:         Documentation problem
 Operating System: Windows
 PHP Version:      4.2.3,4.3.0-dev
 New Comment:

It's not possible to pass third parameter by reference with
allow_call_time_pass_reference and it's not stated in the
documentation. Thus there is no documentation error.

I only noticed that first parameter is passed by reference.


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

[2003-07-15 07:19:31] glen at delfi dot ee

btw, there's workaround for the issue.
create container array, and work on it

$container = array(&$thing);
array_walk($a, array(&$this, 'count'), $container);

and in 'count' function play on first element of $userData array

see:
http://hellsgate.online.ee/~glen/array_walk2.php

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

[2003-07-15 07:09:18] glen at delfi dot ee

well, i agree with fwu, that
1. using ampersand = passing by reference
2. using without = passing a copy

maybe James should look at this example, understanding the
differences:

http://hellsgate.online.ee/~glen/array_walk.php

and, besides, there's no way to silence pass_by_reference warning.
tried
    @array_walk($a, array(&$this, 'count'), &$c);
and
    array_walk($a, array(&$this, 'count'), @&$c);

also tested on 5.0.0b1

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

[2002-11-26 19:25:50] tater at potatoe dot com

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.

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

[2002-10-04 03:04:31] fvu at wanadoo dot nl

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 16:27:08] [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

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

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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