mt_srand

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

seed

An arbitrary integer seed value.

mode

Use 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;

?>
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2 · seed

<?

$seed = time();

mt_srand($seed);

$mt_randreturn = mt_rand();

echo $mt_randreturn;

?>
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3 · mode

<?

$seed = time();
$mode = MT_RAND_PHP;

mt_srand($seed, $mode);

$mt_randreturn = mt_rand();

echo $mt_randreturn;

?>
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getrandmax

lcg_value

mt_getrandmax

mt_rand

rand

srand

PHP

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