PHP mt_srand Function – Seeding the Random Number Generator

The mt_srand() function in PHP seeds the Mersenne Twister random number generator with an optional integer seed; if no seed is supplied, PHP uses a default value.

Parameter int $seed – optional seed value.

Return value

None.

Example

<?php
// seed with microseconds
function make_seed() {
    list($usec, $sec) = explode(' ', microtime());
    return (float)$sec + (float)($usec * 100000);
}
mt_srand(make_seed());
$randval = mt_rand();
echo $randval;
?>

Sample output:

721705391