How to shuffle an array

Short answer

shuffle() shuffles the array in place:

<?php
 
$cards = ['A', 'K', 'Q', 'J'];
shuffle($cards);
 
echo implode(' ', $cards);

Keeping the keys

shuffle() loses the keys. To keep them, shuffle the keys and rebuild the array:

<?php
 
$prices = ['tea' => 250, 'coffee' => 400, 'juice' => 180];
 
$keys = array_keys($prices);
shuffle($keys);
 
$shuffled = [];
 
foreach ($keys as $key) {
    $shuffled[$key] = $prices[$key];
}
 
echo json_encode($shuffled);

Several random elements

array_rand() returns random keys:

<?php
 
$winners = ['Anna', 'Oleg', 'Ivan', 'Maria', 'Petr'];
 
foreach (array_rand($winners, 2) as $key) {
    echo $winners[$key], ' ';
}

Functions used in this recipe

shuffle — Shuffles the elements of an array into a random order.
array_rand — Returns a random key of an array.
random_int — Returns a random integer from a range.