`array_group_by` helper function does not accept array of objects

[daveherman71]

PHP Version

8.4

CodeIgniter4 Version

4.7.2

CodeIgniter4 Installation Method

Composer (using codeigniter4/appstarter)

Which operating systems have you tested for this bug?

Windows

Which server did you use?

cli-server (PHP built-in webserver)

Environment

production, development

Database

No response

What happened?

I have an array of objects. Each object contains a property called group. I would like to generate a multi-dimensional array where the keys are the group name and the values are an array of each object that matches that key. My code is as follows:

helper('array');
$groupedArray = array_group_by($originalArray, [ 'group' ]);

I get the following error:

[TypeError]
CodeIgniter\Helpers\Array\ArrayHelper::arrayAttachIndexedValue(): Argument #2 ($row) must be of type array, stdClass given, called in C:\inetpub\wwwroot\ims\vendor\codeigniter4\framework\system\Helpers\Array\ArrayHelper.php on line 197
at SYSTEMPATH\Helpers\Array\ArrayHelper.php:209

Steps to Reproduce

helper('array');

$json = '[{ "id": 1, "name": "Giraffe", "group": "Mammals" }, { "id": 2, "name": "Zebra", "group": "Mammals" }, { "id": 3, "name": "Crow", "group": "Birds" }]';

$groupedArray = array_group_by(json_decode($json), [ 'group' ]);

print_r($groupedArray);

Expected Output

I expected to get the following output

Array
(
    [Mammals] => Array
        (
            [0] => stdClass Object
                (
                    [id] => 1
                    [name] => Giraffe
                    [group] => Mammals
                )

            [1] => stdClass Object
                (
                    [id] => 2
                    [name] => Zebra
                    [group] => Mammals
                )

        )

    [Birds] => Array
        (
            [0] => stdClass Object
                (
                    [id] => 3
                    [name] => Crow
                    [group] => Birds
                )
        )
)

Anything else?

No response

[michalsn]

This is not a bug. array_group_by() is designed to work with arrays of arrays, and object rows are not supported at the moment. Supporting arrays of objects would be an enhancement/feature request.