mt_srand

(PHP 3 >= 3.0.6, PHP 4, PHP 5)

mt_srand -- Seed the better random number generator

Description

void mt_srand ( [int seed] )

Seeds the random number generator with seed. Since PHP 4.2.0, the seed becomes optional and defaults to a random value if omitted.

範例 1. mt_srand() 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();
?>

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See also: mt_rand(), mt_getrandmax(), and srand().