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 or with a random value if no seed is given.

Note: As of PHP 4.2.0, there is no need to seed the random number generator with srand() or mt_srand() as this is now done automatically.

Parameters

seed

An optional seed value

ChangeLog

VersionDescription
Since 4.2.0 The seed becomes optional and defaults to a random value if omitted.

Examples

Example 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();
?>

See Also

mt_rand()
mt_getrandmax()
srand()