Random\Randomizer::getBytesFromString
(PHP 8 >= 8.3.0)
Random\Randomizer::getBytesFromString — Get random bytes from a source string
说明
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.
参数
返回值
A string containing the requested number of random bytes taken from the input string.
错误／异常
-
If
stringis empty, a ValueError will be thrown. -
If the value of
lengthis less than1, a ValueError will be thrown. -
底层
Random\Randomizer::$engine的 Random\Engine::generate() 方法抛出的任何 Throwable。
示例
示例 #1 Random\Randomizer::getBytesFromString() example
<?php
$randomizer = new \Random\Randomizer();
printf(
"%s.example.com",
$randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
);
?>以上示例的输出类似于：
3zsw04eiubcf82jd.example.com
示例 #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));
?>以上示例的输出类似于：
11551-80418-27047-42075
示例 #3 Select from a string with a non-uniform distribution
<?php
$randomizer = new \Random\Randomizer();
echo $randomizer->getBytesFromString('aaaaabcdef', 20);
?>以上示例的输出类似于：
fddacbeaaeaaacaaaaca
参见
- Random\Randomizer::getBytes() - Get random bytes
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