Bug #54931 [Opn->Tbd]: print_r does not reset() array pointer
| From: | johannes@php.net | Date: | Wed, 25 May 2011 23:54:24 +0000 |
| Subject: | Bug #54931 [Opn->Tbd]: print_r does not reset() array pointer | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-160966@lists.php.net to get a copy of this message | ||
Edit report at http://bugs.php.net/bug.php?id=54931&edit=1
ID: 54931
Updated by: johannes@php.net
Reported by: todd at magnifisites dot com
Summary: print_r does not reset() array pointer
-Status: Open
+Status: To be documented
Type: Bug
Package: Arrays related
Operating System: Any
PHP Version: 5.3.6
Block user comment: N
Private report: N
New Comment:
As print_r is aimed as a debugging help we should document this as
"undefined" behavior so we can change it any time. Users should still be
advised to use reset() if they want a defined state.
Previous Comments:
------------------------------------------------------------------------
[2011-05-25 23:27:57] todd at magnifisites dot com
Description:
------------
The PHP documentation states:
Remember that print_r() will move the array pointer to the end. Use
reset() to bring it back to beginning.
But after using print_r() on an array, the array pointer is not reset.
This is the same as Bug #8289 from PHP 4 in the year 2000:
http://bugs.php.net/bug.php?id=8289
Test script:
---------------
$arr['a'] = 'Apple';
$arr['b'] = 'Banana';
$arr['c'] = 'Corn';
print_r($arr);
//reset($arr);
while(list($k,$v) = each($arr))
echo "$k => $v\n";
Expected result:
----------------
Since print_r moves the array pointer to the end I would expect FALSE to
be returned by each() and nothing to be printed.
However, I also note that foreach() has some side effects so perhaps
this is not necessarily a bug but a documentation issue? foreach()
notes:
http://www.php.net/manual/en/control-structures.foreach.php
Note:
Unless the array is referenced, foreach operates on a copy of the
specified array and not the array itself. foreach has some side effects
on the array pointer. Don't rely on the array pointer during or after
the foreach without resetting it.
Actual result:
--------------
Array
(
[a] => Apple
[b] => Banana
[c] => Corn
)
a => Apple
b => Banana
c => Corn
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=54931&edit=1