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),); $b = array("0.2" => new cr(9), "0.5" => new cr(22), 0 => new cr(3), 1=> new cr(4), 2 => new cr(-15),);
Note:
Please note that this function only checks one dimension of a n-dimensional
array. Of course you can check deeper dimensions by using
array_udiff($array1[0], $array2[0], "data_compare_func");.