Seeds the Mersenne Twister Random Number Generator
Note: There is no need to seed the random number generator with mt_srand() as this is done automatically.
Syntax
mt_srand ([ int $seed [, int $mode = MT_RAND_MT19937 ]] ) : void
Parameters
seedAn arbitrary integer seed value.
modeUse one of the following constants to specify the implementation of the algorithm to use.
| Constant | Description |
|---|---|
| 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. |
Return
No value is returned.
Examples
1 · void
<? mt_srand(); $mt_randreturn = mt_rand(); echo $mt_randreturn; ?>
1501404696
2 · seed
<? $seed = time(); mt_srand($seed); $mt_randreturn = mt_rand(); echo $mt_randreturn; ?>
761378501
3 · mode
<? $seed = time(); $mode = MT_RAND_PHP; mt_srand($seed, $mode); $mt_randreturn = mt_rand(); echo $mt_randreturn; ?>
761378501
