Random\Randomizer::getBytesFromString
(PHP 8 >= 8.3.0)
Random\Randomizer::getBytesFromString — Get random bytes from a source string
Description
Generates a string containing uniformly selected random bytes from the
input string with the requested length.
The chance for a byte to be selected is proportional to its share
of the input string. If each byte occurs
the same amount of times, each byte is equally likely to be selected.
Liste de paramètres
-
string -
The chaîne de caractères from which the returned bytes are selected.
-
length -
The length of the random chaîne de caractères that should be returned in bytes; must be
1or greater.
Valeurs de retour
A chaîne de caractères containing the requested number of random bytes taken from the input string.
Erreurs / Exceptions
-
If
stringis empty, a ValueError will be thrown. -
If the value of
lengthis less than1, a ValueError will be thrown. -
Tout Throwables lancé par la méthode Random\Engine::generate()
du
Random\Randomizer::$enginesous-jacent.
Exemples
Exemple #1 Random\Randomizer::getBytesFromString() example
<?php
$randomizer = new \Random\Randomizer();
printf(
"%s.example.com",
$randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
);
?>Résultat de l'exemple ci-dessus est similaire à :
3zsw04eiubcf82jd.example.com
Exemple #2 Generate a random code for multi-factor authentication
<?php
// The Secure engine is the default, but we make it explicit, because
// multi-factor codes are security sensitive.
$randomizer = new \Random\Randomizer(new \Random\Engine\Secure());
echo implode('-', str_split($randomizer->getBytesFromString('0123456789', 20), 5));
?>Résultat de l'exemple ci-dessus est similaire à :
11551-80418-27047-42075
Exemple #3 Select from a string with a non-uniform distribution
<?php
$randomizer = new \Random\Randomizer();
echo $randomizer->getBytesFromString('aaaaabcdef', 20);
?>Résultat de l'exemple ci-dessus est similaire à :
fddacbeaaeaaacaaaaca
Voir aussi
- Random\Randomizer::getBytes() - Get random bytes
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