Random\Randomizer::pickArrayKeys
(PHP 8 >= 8.2.0)
Random\Randomizer::pickArrayKeys — Select random array keys
Beschreibung
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.
Parameter-Liste
-
array -
The array whose array keys are selected.
-
num -
The number of array keys to return; must be between
1and the number of elements inarray.
Rückgabewerte
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().
Fehler/Exceptions
-
If
numis less than1or greater than the number of elements inarray, a ValueError will be thrown. -
Alle Throwables, die von der Methode Random\Engine::generate() der
zugrundeliegenden
Random\Randomizer::$engineausgelöst werden.
Beispiele
Beispiel #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";
?>Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
Keys: yellow, purple Keys: red, green, yellow
Beispiel #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";
?>Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
Values: 🍎, 🍇
Siehe auch
- array_keys() - Liefert alle Schlüssel oder eine Teilmenge aller Schlüssel eines Arrays
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