Random\Randomizer::getBytesFromString
(PHP 8 >= 8.3.0)
Random\Randomizer::getBytesFromString — Get random bytes from a source string
Descrizione
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.
Elenco dei parametri
Valori restituiti
A string containing the requested number of random bytes taken from the input string.
Errori/Eccezioni
-
If
stringis empty, a ValueError will be thrown. -
If the value of
lengthis less than1, a ValueError will be thrown. -
Any Throwables thrown by the Random\Engine::generate() method
of the underlying
Random\Randomizer::$engine.
Esempi
Example #1 Random\Randomizer::getBytesFromString() example
<?php
$randomizer = new \Random\Randomizer();
printf(
"%s.example.com",
$randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
);
?>Il precedente esempio visualizzerà qualcosa simile a:
3zsw04eiubcf82jd.example.com
Example #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));
?>Il precedente esempio visualizzerà qualcosa simile a:
11551-80418-27047-42075
Example #3 Select from a string with a non-uniform distribution
<?php
$randomizer = new \Random\Randomizer();
echo $randomizer->getBytesFromString('aaaaabcdef', 20);
?>Il precedente esempio visualizzerà qualcosa simile a:
fddacbeaaeaaacaaaaca
Vedere anche:
- Random\Randomizer::getBytes() - Get random bytes
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