mt_getrandmax
mt_srand
Math Functions
PHP Manual

# mt_rand

(PHP 4, PHP 5)

mt_rand — Generate a better random value

### Description

int mt_rand ([ int `$min` ], int `$max` )

Many random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand() function. The mt_rand() function is a drop-in replacement for this. It uses a random number generator with known characteristics using the » Mersenne Twister, which will produce random numbers four times faster than what the average libc rand() provides.

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

> Note: As of PHP 4.2.0, there is no need to seed the random number generator with srand() or mt_srand() as this is now done automatically.

### Parameters

`min`

  Optional lowest value to be returned (default: 0)

`max`

  Optional highest value to be returned (default: RAND_MAX)

### Return Values

A random integer value between `min` (or 0) and `max` (or RAND_MAX, inclusive)

### ChangeLog

Version | Description
--- | ---
Since 3.0.7 | In versions before 3.0.7 the meaning of `max` was `range` . To get the same results in these versions the short example should be rand (5, 11) to get a random number between 5 and 15.

### Examples

Example#1 mt_rand() example

`<?php
echo mt_rand() . "\n";
echo mt_rand() . "\n";
echo mt_rand(5, 15);
?>`

The above example will output something similar to:

    1604716014
    1478613278
    6

### See Also

- mt_srand()
- mt_getrandmax()
- rand()

mt_getrandmax
mt_srand
Math Functions
PHP Manual