rand

(PHP 4, PHP 5, PHP 7, PHP 8)

rand — Generate a random integer

Description

rand(): int

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

If called without the optional min, max arguments rand() returns a pseudo-random integer between 0 and getrandmax(). If you want a random number between 5 and 15 (inclusive), for example, use rand(5, 15).

Caution

This function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(), random_bytes(), or openssl_random_pseudo_bytes() instead.

Note: On some platforms (such as Windows), getrandmax() is only 32767. If you require a range larger than 32767, specifying min and max will allow you to create a range larger than this, or consider using mt_rand() instead.

Note: As of PHP 7.1.0, rand() uses the same random number generator as mt_rand(). To preserve backwards compatibility rand() allows max to be smaller than min as opposed to returning false as mt_rand().

Parameters

min: The lowest value to return (default: 0)
max: The highest value to return (default: getrandmax())

Return Values

A pseudo random value between min (or 0) and max (or getrandmax(), inclusive).

Changelog

Version	Description
7.2.0	rand() has received a bug fix for a modulo bias bug. This means that sequences generated with a specific seed may differ from PHP 7.1 on 64-bit machines.
7.1.0	rand() has been made an alias of mt_rand().

Examples

Example #1 rand() example


<?php
echo rand() . "\n";
echo rand() . "\n";

echo rand(5, 15);
?>

The above example will output something similar to:

7771
22264
11

Notes

Warning

min max range must be within the range getrandmax(). i.e. (max - min) <= getrandmax() Otherwise, rand() may return poor-quality random numbers.