Edit report at https://bugs.php.net/bug.php?id=60198&edit=1
ID: 60198
Updated by: ras...@php.net
Reported by: simon at simon dot geek dot nz
Summary: Array to string notice from array functions
-Status: Open
+Status: Bogus
Type: Bug
Package: *General Issues
PHP Version: 5.4SVN-2011-11-02 (SVN)
Block user comment: N
Private report: N
New Comment:
The problem here is that these functions aren't recursive. They just go one
level deep and assume arrays of scalars. This means that the notice is a good
idea because the result when you pass it nested arrays is likely not the one
you
wanted.
For example. If we change your code example slightly:
$left = [ 1, 2, [3] ];
$right = [2, 'Array'];
What should the intersection of these two be? Surely just the '2' since there
is
no nested array with a 3 in $right and there is no string 'Array' in $left. But
the actual output is: [ 2, [3] ]
Oops! That's not what we expected and that is why this result gives you a
notice
telling you that the result is likely flawed because of an array to string
conversion. Now, it might be nice if array_intersect was smarter and could
handle nested arrays, but that would be a different feature enhancement bug.
It also looks like this is well-documented. The array_intersect() doc page has
this highlighted note:
Note: Two elements are considered equal if and only if (string) $elem1 ===
(string) $elem2. In words: when the string representation is the same.
Previous Comments:
------------------------------------------------------------------------
[2011-11-11 00:05:29] chx1975 at gmail dot com
This affects the Drupal project. All our tests are failing because of this bug.
We see it with array_intersect_assoc().
------------------------------------------------------------------------
[2011-11-02 08:33:27] simon at simon dot geek dot nz
Description:
------------
Some of the array_* functions that compare elements in multiple arrays do so by
(string)$elem1 === (string)$elem2.
If $elem1 or $elem2 is an array, then the array to string notice is thrown.
Two examples of functions that can throw this are array_intersect() and
array_diff().
If these functions are not expected to take arrays with other arrays as values,
this should be mentioned on the documentation pages.
Test script:
---------------
<?php
$left = array('b', array('a'));
$right = array('a', 'd');
print_r(array_intersect($left, $right));
print_r(array_diff($left, $right));
Expected result:
----------------
Array
(
)
Array
(
[0] => b
[1] => Array
(
[0] => a
)
)
Actual result:
--------------
PHP Notice: Array to string conversion in /Users/simon/test.php on line 4
PHP Notice: Array to string conversion in /Users/simon/test.php on line 4
PHP Notice: Array to string conversion in /Users/simon/test.php on line 5
PHP Notice: Array to string conversion in /Users/simon/test.php on line 5
PHP Notice: Array to string conversion in /Users/simon/test.php on line 5
Notice: Array to string conversion in /Users/simon/test.php on line 4
Notice: Array to string conversion in /Users/simon/test.php on line 4
Array
(
)
Notice: Array to string conversion in /Users/simon/test.php on line 5
Notice: Array to string conversion in /Users/simon/test.php on line 5
Notice: Array to string conversion in /Users/simon/test.php on line 5
Array
(
[0] => b
[1] => Array
(
[0] => a
)
)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=60198&edit=1
