PHP Manual
CSPRNG Functions
Generates cryptographically secure pseudo-random integers

random_int

(PHP 7)

random_int — Generates cryptographically secure pseudo-random integers

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 an Exception 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, which must be PHP_INT_MIN or higher.
max: The highest value to be returned, which must be less than or equal to PHP_INT_MAX.

Return Values

Returns a cryptographically secure random integer in the range min to max, inclusive.

Errors/Exceptions

If an appropriate source of randomness cannot be found, an Exception will be thrown.
If invalid parameters are given, a TypeError will be thrown.
If max is less than min, an Error will be thrown.

Examples

Example #1 random_int() example

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

The above example will output something similar to:

int(248)
int(-898)

Php/docs/function.random-int

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