PHP: array_udiff

Description

array array_udiff ( array array1, array array2 [, array ..., callback data_compare_func] )

array_udiff() returns an array containing all the values of array1 that are not present in any of the other arguments. Note that keys are preserved. For the comparison of the data data_compare_func is used. It must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second. This is unlike array_diff() which uses an internal function for comparing the data.

Example 1. array_udiff() example

<?php class cr { private $priv_member; function cr($val) { $this->priv_member = $val; } function comp_func_cr($a, $b) { if ($a->priv_member === $b->priv_member) return 0; return ($a->priv_member > $b->priv_member)? 1:-1; } } $a = array("0.1" => new cr(9), "0.5" => new cr(12), 0 => new cr(23), 1=> new cr(4), 2 => new cr(-15),); $b = array("0.2" => new cr(9), "0.5" => new cr(22), 0 => new cr(3), 1=> new cr(4), 2 => new cr(-15),); $result = array_udiff($a, $b, array("cr", "comp_func_cr")); print_r($result); ?>
The above example will output:
Array ( [0.5] => cr Object ( [priv_member:private] => 12 ) [0] => cr Object ( [priv_member:private] => 23 ) )

Note: Please note that this function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using array_udiff($array1[0], $array2[0], "data_compare_func");.

User Contributed Notes
array_udiff

dmhouse at gmail dot com
20-Jan-2005 03:44


Very easy way of achieving a case-insensitive version of array_diff (or indeed array_diff_assoc, array_intersect or any of these types of functions which have a similar function that takes a callback function as one of their parameters):



array_udiff($array1, $array2, 'strcasecmp');



This works because strcasecmp() compares two strings case-insensitively, as compared to the array_diff() which compares two strings by using the == operator, which is case-sensitive.

aidan at php dot net
28-May-2004 09:11


This functionality is now implemented in the PEAR package PHP_Compat.



More information about using this function without upgrading your version of PHP can be found on the below link:



http://pear.php.net/package/PHP_Compat