Bug #53724 [Opn]: array_diff like methods compares false as identity and true as equal

From: Date: Wed, 12 Jan 2011 13:27:34 +0000
Subject: Bug #53724 [Opn]: array_diff like methods compares false as identity and true as equal
References: 1  Groups: php.bugs 
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Edit report at http://bugs.php.net/bug.php?id=53724&edit=1

 ID:                 53724
 User updated 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:

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).


Previous Comments:
------------------------------------------------------------------------
[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"
}



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



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