How to sort an array

Short answer

sort() sorts the array itself in ascending order:

<?php
 
$numbers = [3, 1, 2];
sort($numbers);
 
echo implode(', ', $numbers);

Output:

1, 2, 3

Descending order

rsort() sorts in reverse order:

<?php
 
$numbers = [3, 1, 2];
rsort($numbers);
 
echo implode(', ', $numbers);

Output:

3, 2, 1

By a field

usort() sorts an array of records with a comparison function. The <=> operator returns -1, 0 or 1:

<?php
 
$users = [
    ['name' => 'Anna', 'age' => 30],
    ['name' => 'Oleg', 'age' => 25],
];
usort($users, fn ($a, $b) => $a['age'] <=> $b['age']);
 
echo implode(', ', array_column($users, 'name'));

Output:

Oleg, Anna

Associative arrays

sort() renumbers the keys. To keep them, use asort():

<?php
 
$prices = ['tea' => 150, 'milk' => 90];
asort($prices);
 
print_r($prices);

Output:

Array
(
    [milk] => 90
    [tea] => 150
)

Thanks for reading!

Short answer

Descending order

By a field

Associative arrays

Functions used in this recipe

Thanks for reading!