PHP RFC: Add array_group function

• Version: 2.0
• Date: 2021-11-28
• Author: Hassan Ahmed, 7snovic@gmail.com
• Status: Declined
• First Published at: https://wiki.php.net/rfc/array_column_results_grouping

This RFC is to implement a new function to PHP that upgrades the functionality of array_column to group similar results that share the same index_key into a multidimensional array. the current behavior of array_column is to return a single result and ignore the rest of the results that share the same index.

This RFC is to add a new function called array_group

array_group(array $array, int|string|null $column_key, int|string|null $index_key = null)

The current behavior is when you have multiple elements share the same key, it will be overwritten. let's assume that we have the following.

<?php
 
$array = [
    ['id' => 1, 'name' => 'hassan'],
    ['id' => 2, 'name' => 'sara'],
    ['id' => 3, 'name' => 'selim'],
    ['id' => 4, 'name' => 'chris'],
    ['id' => 5, 'name' => 'sara'],
];

when we use array_column with this the output will be

print_r(array_column($array, null, 'name'));
Array
(
    [hassan] => Array
        (
            [id] => 1
            [name] => hassan
        )
 
    [sara] => Array
        (
            [id] => 5
            [name] => sara
        )
 
    [selim] => Array
        (
            [id] => 3
            [name] => selim
        )
 
    [chris] => Array
        (
            [id] => 4
            [name] => chris
        )
 
)

The RFC implements a new function called array_group to group the results in an indexed array to group all the similar elements, so we can use :

print_r(array_group($array, null, 'name'));
Array
(
    [hassan] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [name] => hassan
                )
 
        )
 
    [sara] => Array
        (
            [0] => Array
                (
                    [id] => 2
                    [name] => sara
                )
 
            [1] => Array
                (
                    [id] => 5
                    [name] => sara
                )
 
        )
 
    [selim] => Array
        (
            [0] => Array
                (
                    [id] => 3
                    [name] => selim
                )
 
        )
 
    [chris] => Array
        (
            [0] => Array
                (
                    [id] => 4
                    [name] => chris
                )
 
        )
 
)

No backward incompatible breaks.

Next PHP 8.x, currently PHP 8.2.

Standard ext

Yes/No vote.

Started at : 2021-12-21 Ends at : 2022-01-04

Add array_group function to PHP
Real name	Yes	No
asgrim (asgrim)
ashnazg (ashnazg)
bmajdak (bmajdak)
brandon (brandon)
brzuchal (brzuchal)
crell (crell)
cschneid (cschneid)
galvao (galvao)
geekcom (geekcom)
heiglandreas (heiglandreas)
kguest (kguest)
klaussilveira (klaussilveira)
kocsismate (kocsismate)
levim (levim)
ocramius (ocramius)
patrickallaert (patrickallaert)
svpernova09 (svpernova09)
theodorejb (theodorejb)
thorstenr (thorstenr)
Final result:	0	19
This poll has been closed.

Implementing array_group function