(PHP 4, PHP 5, PHP 7)
mt_srand — Seeds the Mersenne Twister Random Number Generator
$seed
= 0
, int $mode
= MT_RAND_MT19937
) : void
Seeds the random number generator with
seed
or with a random value
if no seed
is given.
Notă: Nu este nevoie de a însămânța generatorul de numere aleatoare cu ajutorul srand() sau mt_srand(), deoarece aceasta se efectuează în mod automat.
seed
An arbitrary int seed value.
mode
Use one of the following constants to specify the implementation of the algorithm to use.
Constant | Descriere |
---|---|
MT_RAND_MT19937 |
Uses the fixed, correct, Mersenne Twister implementation, available as of PHP 7.1.0. |
MT_RAND_PHP |
Uses an incorrect Mersenne Twister implementation which was used as the default up till PHP 7.1.0. This mode is available for backward compatibility. |
Nu este întoarsă nici o valoare.
Versiune | Descriere |
---|---|
7.1.0 | srand() has been made an alias of mt_srand(). |
7.1.0 |
mt_rand() has been updated to use the fixed, correct, version of
the Mersenne Twister algorithm. To fall back to the old behaviour, use mt_srand() with MT_RAND_PHP as the second parameter.
|
Example #1 mt_srand() example
<?php
// seed with microseconds
function make_seed()
{
list($usec, $sec) = explode(' ', microtime());
return $sec + $usec * 1000000;
}
mt_srand(make_seed());
$randval = mt_rand();
?>