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rand

PHP function Edit on GitHub ✎

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

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).

Cryptographically-insecure Mt19937-global-state

Note

Prior to PHP 7.1.0, getrandmax() was only 32767 on some platforms (such as Windows). 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

rand() example

php

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

echo rand(5, 15), "\n";
?>

The above example will output something similar to:

output

7771
22264
11

Notes

Warning

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