PHP Sorting Arrays

How it works

sort reindexes a list of values, asort preserves the key/value association, and ksort orders by keys. Comparator-based sorting needs a consistent negative/zero/positive result. If a report needs a tie-breaker, include one explicitly so its intended order is reviewable. Sorting an input in place is a mutation, so copy it first when another caller still needs the original order.

Run it locally

Run this complete source locally with PHP 8.2 or newer. Save it using the filename shown and run the command below. PHP is not currently available in Bhylu’s browser playground. Apache and MySQL are not needed for an ordinary CLI example.

php -l array-sorting.php
php array-sorting.php

Download this source as a local PHP lab file. Keep lab files separate from the Bhylu project and production data.

Example

<?php
declare(strict_types=1);

$stock = ["Saw"=>2,"Spade"=>5,"Drill"=>2];
ksort($stock);
foreach ($stock as $name=>$count) echo "$name: $count\n";
$rows = [["id"=>3,"count"=>2],["id"=>1,"count"=>2]];
usort($rows, fn(array $a,array $b): int => ($a["count"] <=> $b["count"]) ?: ($a["id"] <=> $b["id"]));
echo "First id: ", $rows[0]["id"], "\n";

Expected result

Drill: 2
Saw: 2
Spade: 5
First id: 1

Key sorting keeps each stock quantity attached to its name. The row comparator orders by count and then ID, which makes equal counts predictable by the stated rule. The sorted list has positional keys; the record’s id field still carries the stable business identity.