Get a cryptographically secure, uniformly selected integer

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- Get a cryptographically secure, uniformly selected integer

# random_int

(PHP 7, PHP 8)

random_int — Get a cryptographically secure, uniformly selected integer

### Description

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

Generates a uniformly selected integer between the given minimum and maximum.

The randomness generated by this function is suitable for all applications, including the generation of long-term secrets, such as encryption keys.

The sources of randomness in the order of priority are as follows:

- Linux: » getrandom(), /dev/urandom

- FreeBSD >= 12 (PHP >= 7.3): » getrandom(), /dev/urandom

- Windows (PHP >= 7.2): » CNG-API

  Windows: » CryptGenRandom

- macOS (PHP >= 8.2; >= 8.1.9; >= 8.0.22 if CCRandomGenerateBytes is available at compile time): CCRandomGenerateBytes()

  macOS (PHP >= 8.1; >= 8.0.2): arc4random_buf(), /dev/urandom

- NetBSD >= 7 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), /dev/urandom

- OpenBSD >= 5.5 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), /dev/urandom

- DragonflyBSD (PHP >= 8.1): » getrandom(), /dev/urandom

- Solaris (PHP >= 8.1): » getrandom(), /dev/urandom

- Any combination of operating system and PHP version not previously mentioned: /dev/urandom
- If none of the sources are available or they all fail to generate randomness, 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`, a 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)

### See Also

- Random\Randomizer::getInt() - Get a uniformly selected integer
- random_bytes() - Get cryptographically secure random bytes