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str_shuffle

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

str_shuffle — Randomly shuffles a string

Description

str_shuffle(string $string): string

str_shuffle() shuffles a string. One permutation of all possible is created.

Caution

This function does not generate cryptographically secure values, and must not be used for cryptographic purposes, or purposes that require returned values to be unguessable.

If cryptographically secure randomness is required, the Random\Randomizer may be used with the Random\Engine\Secure engine. For simple use cases, the random_int() and random_bytes() functions provide a convenient and secure API that is backed by the operating system’s CSPRNG.

Caution

This function uses the global Mt19937 (“Mersenne Twister”) instance as the source of randomness and thus shares its state with all other functions using the global Mt19937. Using any of these functions advances the sequence for all the other functions, regardless of scope.

Generating repeatable sequences by seeding mt_srand() or srand() with a known value will also yield repeatable output from this function.

Prefer using Random\Randomizer methods in all newly written code.

Parameters

string

The input string.

Return Values

Returns the shuffled string.

Changelog

Version Description
7.1.0 The internal randomization algorithm has been changed to use the » Mersenne Twister Random Number Generator instead of the libc rand function.

Examples

Example #1 str_shuffle() example

<?php
$str = 'abcdef';
$shuffled = str_shuffle($str);

// This will echo something like: bfdaec
echo $shuffled;
?>

See Also