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Generate a better random value 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,maxarguments 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).Parameters
minOptional lowest value to be returned (default: 0)
maxOptional highest value to be returned (default: mt_getrandmax())
Return Values
A random integer value between
min(or 0) andmax(or mt_getrandmax(), inclusive)Changelog
Version Description 4.2.0 The random number generator is seeded automatically. 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 6Notes
CautionThe distribution of mt_rand() return values is biased towards even numbers on 64-bit builds of PHP when
maxis beyond 2^32.See Also
- mt_srand() - Seed the better random number generator
- mt_getrandmax() - Show largest possible random value
- rand() - Generate a random integer