note 60976 deleted from function.array-diff by nlopess
| From: | nlopess@php.net | Date: | Sun, 22 Jan 2006 11:28:52 +0000 |
| Subject: | note 60976 deleted from function.array-diff by nlopess | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-102236@lists.php.net to get a copy of this message | ||
Note Submitter: Jappie
----
Reading the comments, I've seen a lot of variations of diff-ing 2 arrays. But what if you need
to diff more than 2 arrays? What if you don't know how many arrays you need to diff?
This function is an anwer to that:
<?php
# An extention to array_diff:
# It returns an array of all values not present in all arrays given, or null if all match.
# The arrays to compare must be placed in an other array, which is used as argument.
# Returns false if the given array is invalid.
function array_rdiff ($arrays) {
# check if argument is valid.
if (!is_array ($arrays))
return false;
foreach ($arrays as $array)
if (!is_array ($array))
return false;
# set working variables
$diff = null;
$amount = count ($arrays);
$needles = array_shift ($arrays);
# compare
for ($n = 0; $n < $amount; $n++) {
foreach ($needles as $needle) {
$found = true;
foreach ($arrays as $haystack)
if (!in_array ($needle, $haystack))
$found = false;
if (!$found)
$diff[] = $needle;
}
$arrays[] = $needles;
$needles = array_shift ($arrays);
}
return array_unique ($diff);
}
?>
So doing:
<?php
$array1 = array (21, 22, 23);
$array2 = array (21, 12, 23, 24);
$array3 = array (11, 22, 23, 24);
print_r (array_rdiff (array ($array1, $array2, $array3)));
?>
will return:
Array
(
[0] => 21
[1] => 22
[3] => 12
[4] => 24
[5] => 11
)