PHP Functions Essential Reference

mt_srand

void mt_srand(int seed) 

Seeds the random number generator for mt_rand() .

Returns:

Nothing

Description:

This function seeds the random number generator for mt_rand(). The greater the randomness of the initial seed passed to this function, the better the randomness of the numbers later generated by mt_rand().

This function needs to be called only once per script, before any calls to mt_rand().

Version:

PHP 3 since 3.0.6, PHP 4

See also:

getrandmax() 
mt_getrandmax() 
mt_rand() 
rand() 
srand() 

Example:

Seed the Mersenne Twister random number generator

mt_srand((double) microtime() * 1000000);