array_group_by
A PHP function to group an array by a key or set of keys shared between all array members.
Installation
To get the latest version of array_group_by, simply require the project using Composer:
$ composer require jakezatecky/array_group_by
Need support for PHP 5.6? Then run the following:
$ composer require jakezatecky/array_group_by:^1.1.0
If you do not want to use Composer, you can just require the src/array_group_by.php file.
Usage
To use array_group_by, simply pass an array with any number of keys to group by:
$records = [
[
'state' => 'IN',
'city' => 'Indianapolis',
'object' => 'School bus',
],
[
'state' => 'IN',
'city' => 'Indianapolis',
'object' => 'Manhole',
],
[
'state' => 'IN',
'city' => 'Plainfield',
'object' => 'Basketball',
],
[
'state' => 'CA',
'city' => 'San Diego',
'object' => 'Light bulb',
],
[
'state' => 'CA',
'city' => 'Mountain View',
'object' => 'Space pen',
],
];
$grouped = array_group_by($records, 'state', 'city');
Example output:
Array
(
[IN] => Array
(
[Indianapolis] => Array
(
[0] => Array
(
[state] => IN
[city] => Indianapolis
[object] => School bus
)
[1] => Array
(
[state] => IN
[city] => Indianapolis
[object] => Manhole
)
)
[Plainfield] => Array
(
[0] => Array
(
[state] => IN
[city] => Plainfield
[object] => Basketball
)
)
)
[CA] => Array
(
[San Diego] => Array
(
[0] => Array
(
[state] => CA
[city] => San Diego
[object] => Light bulb
)
)
[Mountain View] => Array
(
[0] => Array
(
[state] => CA
[city] => Mountain View
[object] => Space pen
)
)
)
)
Using a Callback
If more complex grouping behavior is desired, you can also pass in a callback function to determine the group key:
$grouped = array_group_by($records, function ($row) {
return $row->city;
});