Bug #52576 [Opn->Bgs]: Variable variables can create invalid variables.
Edit report at http://bugs.php.net/bug.php?id=52576&edit=1
ID: 52576
Updated by: johannes@php.net
Reported by: rquadling@php.net
Summary: Variable variables can create invalid variables.
-Status: Open
+Status: Bogus
Type: Bug
Package: Scripting Engine problem
Operating System: Windows XP SP3
PHP Version: 5.3.3
Block user comment: N
New Comment:
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
Variable names may contain any character.
${',.-+#*#+\\'} = 42;
This is expected.
Previous Comments:
------------------------------------------------------------------------
[2010-08-10 18:21:13] rquadling@php.net
Description:
------------
It seems you can create a variable in $GLOBALS that is not accessible as
a
normal variable.
I found this because I wanted to use variable variables to populate a
nested
array.
Jim Lucas, in http://news.php.net/php.general/307392, comments
that the
use of
eval() may be appropriate in the case.
That aside, the entry that is created in $GLOBALS doesn't follow the
rules for
variable naming in
http://docs.php.net/manual/en/language.variables.basics.php,
namely that '[' and ']' are not valid variable names. I think this
should have t
least produced an E_WARNING.
So, with all of that, I'm not sure if this is a bug or a documentation
problem.
I certainly think it is an edge case.
Regards,
Richard Quadling.
Test script:
---------------
<?php
// Show all errors.
error_reporting(-1);
ini_set('display_errors', 1);
// Expectation was to be able to create a deep array using variable
variables.
$a = 'b[1][2][3]';
$$a = 'Inaccessible?';
print_r($b);
// Hide superglobals
unset($_POST);
unset($_GET);
unset($_SESSION);
unset($_FILES);
unset($_COOKIE);
unset($_SERVER);
unset($argv);
unset($argc);
// Reveals inaccessible variable.
var_dump($GLOBALS);
Expected result:
----------------
Array
(
[1] => Array
(
[2] => Array
(
[3] => Inaccessible?
)
)
)
array(3) {
["GLOBALS"]=>
*RECURSION*
["a"]=>
string(10) "b[1][2][3]"
["b"]=>
array(1) {
[1]=>
array(1) {
[2]=>
array(1) {
[3]=>
string(13) "Inaccessible?"
}
}
}
}
Actual result:
--------------
Notice: Undefined variable: b in - on line 5
array(4) {
["GLOBALS"]=>
*RECURSION*
["a"]=>
string(10) "b[1][2][3]"
["b[1][2][3]"]=>
string(13) "Inaccessible?"
["php_errormsg"]=>
string(21) "Undefined variable: b"
}
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=52576&edit=1
Thread (2 messages)