PHP: random_int

Description

random_int(int $min, int $max): int

Generates cryptographic random integers that are suitable for use where unbiased results are critical, such as when shuffling a deck of cards for a poker game.

The sources of randomness used for this function are as follows:

On Windows, » CryptGenRandom() will always be used. As of PHP 7.2.0, the » CNG-API will always be used instead.
On Linux, the » getrandom(2) syscall will be used if available.
On other platforms, /dev/urandom will be used.
If none of the aforementioned sources are available, then a Random\RandomException will be thrown.

Note: Although this function was added to PHP in PHP 7.0, a » userland implementation is available for PHP 5.2 to 5.6, inclusive.

Parameters

min: The lowest value to be returned.
max: The highest value to be returned.

Return Values

A cryptographically secure, uniformly selected integer from the closed interval [min, max]. Both min and max are possible return values.

Errors/Exceptions

If an appropriate source of randomness cannot be found, a Random\RandomException will be thrown.
If max is less than min, an ValueError will be thrown.

Changelog

Version	Description
8.2.0	In case of a CSPRNG failure, this function will now throw a Random\RandomException. Previously a plain Exception was thrown.

Examples

Example #1 random_int() example


<?php
var_dump(random_int(100, 999));
var_dump(random_int(-1000, 0));
?>

The above example will output something similar to:

int(248)
int(-898)

random_int