(PHP 8 >= 8.2.0)
Random\Randomizer::pickArrayKeys — Select random array keys
public Random\Randomizer::pickArrayKeys(array $array, int $num): array
Uniformly selects num distinct array keys of the input array.
Each key of the input array is equally likely to be returned.
The selection of the array keys depends on the internal structure of the input array. The returned array keys might be different for two equal input arrays and two Random\Engines with identical state, depending on how the input arrays have been created.
arrayThe array whose array keys are selected.
num The number of array keys to return; must be between 1 and the number of elements in array.
An array containing num distinct array keys of array.
The returned array will be a list (array_is_list()). It will be a subset of the array returned by array_keys().
num is less than 1 or greater than the number of elements in array, a ValueError will be thrown. Random\Randomizer::$engine. Example #1 Random\Randomizer::pickArrayKeys() example
<?php
$r = new \Random\Randomizer();
$fruits = [ 'red' => '🍎', 'green' => '🥝', 'yellow' => '🍌', 'pink' => '🍑', 'purple' => '🍇' ];
// Pick 2 random array keys:
echo "Keys: ", implode(', ', $r->pickArrayKeys($fruits, 2)), "\n";
// Pick another 3:
echo "Keys: ", implode(', ', $r->pickArrayKeys($fruits, 3)), "\n";
?> The above example will output something similar to:
Keys: yellow, purple Keys: red, green, yellow
Example #2 Picking random values
<?php
$r = new \Random\Randomizer();
$fruits = [ 'red' => '🍎', 'green' => '🥝', 'yellow' => '🍌', 'pink' => '🍑', 'purple' => '🍇' ];
$keys = $r->pickArrayKeys($fruits, 2);
// Look up the values for the picked keys.
$selection = array_map(
static fn ($key) => $fruits[$key],
$keys
);
echo "Values: ", implode(', ', $selection), "\n";
?> The above example will output something similar to:
Values: 🍎, 🍇
© 1997–2025 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/random-randomizer.pickarraykeys.php