mt_rand
(PHP 4, PHP 5)
mt_rand — Generate a better random value
Description
int mt_rand
( void
)
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
mt_getrandmax(). 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: mt_getrandmax())
Return Values
A random integer value between min
(or 0)
and max
(or mt_getrandmax(), inclusive)
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:
Load balance : Server 04
