Random\Randomizer::getBytesFromString

(PHP 8 >= 8.3.0)

Random\Randomizer::getBytesFromStringGet random bytes from a source string

Descrizione

public Random\Randomizer::getBytesFromString(string $string, int $length): string

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

string

The string from which the returned bytes are selected.

length

The length of the random string that should be returned in bytes; must be 1 or greater.

Valori restituiti

A string containing the requested number of random bytes taken from the input string.

Errori/Eccezioni

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:

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