Edit report at http://bugs.php.net/bug.php?id=53724&edit=1
ID: 53724
Comment by: lukas dot starecek at centrum dot cz
Reported by: lukas dot starecek at centrum dot cz
Summary: array_diff like methods compares false as identity
and true as equal
Status: Open
Type: Bug
Package: Arrays related
Operating System: Irrelevant
PHP Version: 5.3.5
Block user comment: N
Private report: N
New Comment:
Ah I did not noticed this "grey" part of method documentation in
examples. You are right, documentation says it, but imho in not so clear
way. I have read only specifications, not examples. Imho documentation
could be a little bit more exact, because this is important.
So sadly this functions are designed only for string comparison, not for
general variable comparison :-/ .
My fault, bogus, sorry. But think about functions of this kind for
general variables comparison, not only for string comparison :-) .
Previous Comments:
------------------------------------------------------------------------
[2011-02-20 16:20:18] tbrasta at gmail dot com
This is not a bug. The function is operating exactly as stated in the
documentation, i.e. casted to string values are compared. Since (string)
0 = "0", (string) false = "" and (string) "0" = "0" but "0" !== "", you
get the result as it should be.
------------------------------------------------------------------------
[2011-01-12 14:27:34] lukas dot starecek at centrum dot cz
A little mistake, '' behaves as same with false, so problem is only in
comparing 0 and '0' (and maybee some other variables I did not used).
------------------------------------------------------------------------
[2011-01-12 14:16:39] lukas dot starecek at centrum dot cz
Description:
------------
array_diff functions compares boolean false as identity (operator "===")
and boolean true as equal (operator "==") so behaves inconsistently. It
should compare all values in same way and in my opinion it should
compare as equals ("==") or have argument (or another mechanism) how to
set whether compare by equal or identity.
As example I use array_diff_assoc but I think it will probably behave
simmilary with another array realted functions (array_diff%,
array_intersect%). In expected result I suppose comparing as equal
(operator '==').
In example you can see, that array_diff_assoc behaves in such way that 0
or '0' or '' is not same as false, but 1 or '1' is same as true. So
false is compared like '===' and true is compared like '=='. Because 0
is same as '0' and 1 is same as '1' I suppose, that this problem is only
for boolean false value.
Test script:
---------------
$arr1 = array('a' => 0, 'b' => 1, 'c' => '0', 'd' => '1', 'e'
=> '', 'f' => false, 'g' => true, 'h' => 0, 'i' => 1);
$arr2 = array('a' => false, 'b' => true, 'c' => false, 'd' => true, 'e'
=> false, 'f' => false, 'g' => true, 'h' => '0', 'i' => '1');
var_dump(array_diff_assoc($arr1, $arr2));
Expected result:
----------------
array(0) {
}
Actual result:
--------------
array(2) {
["a"]=>
int(0)
["c"]=>
string(1) "0"
}
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=53724&edit=1
