note 116714 added to function.array-combine
| From: | ilanfir at gmail dot com | Date: | Sun, 15 Feb 2015 10:59:01 +0000 |
| Subject: | note 116714 added to function.array-combine | ||
| Groups: | php.notes | ||
| Request: | Send a blank email to php-notes+get-201734@lists.php.net to get a copy of this message | ||
I recently had to flip an array and group the elements by value, this snippet will do that:
<?php
function flipAndGroup($input) {
$outArr = array();
array_walk($input, function($value, $key) use (&$outArr) {
if(!isset($outArr[$value]) || !is_array($outArr[$value])) {
$outArr[$value] = [];
}
$outArr[$value][] = $key;
});
return $outArr;
}
?>
Example:
<?php
$users_countries = array(
'username1' => 'US',
'user2' => 'US',
'newuser' => 'GB'
);
print_r(flipAndGroup($users_countries));
?>
Returns:
Array
(
[US] => Array
(
[0] => username1
[1] => user2
)
[GB] => Array
(
[0] => newuser
)
)
----
Server IP: 72.52.91.14
Probable Submitter: 82.80.159.227
----
Manual Page -- http://php.net/manual/en/function.array-combine.php
Edit -- https://master.php.net/note/edit/116714
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Del: in docs -- https://master.php.net/note/delete/116714/in+docs
Del: other reasons-- https://master.php.net/note/delete/116714
Reject -- https://master.php.net/note/reject/116714
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