Table of Contents

PHP RFC: Add array_group function

Introduction

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.

Proposal

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
                )
 
        )
 
)

Backward Incompatible Changes

No backward incompatible breaks.

Proposed PHP Version(s)

Next PHP 8.x, currently PHP 8.2.

RFC Impact

To Existing Extensions

Standard ext

Proposed Voting Choices

Yes/No vote.

Voting

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.

Implementation

Implementing array_group function