Version: 1.0
Type: Function
Category: Math Functions
License: GNU General Public License
Description: Handy drop-in function to replace PHP’s stock array_rand, but uses PHP’s mt_srand and mt_rand functions. The Mersenne Twister is much more random, and 4 times faster than standard rand() functions.
<?php /* mt_array_rand - adapted from fake_array_rand func by [email protected] */ /* copyleft (c) 2002 Will Fischer <[email protected]> */ function mt_array_rand($array, $num_req = 1) { /* Ensure that $num_req has a sane value */ $num_req > 0 or $num_req = 1; $count = count ($array); for ($n=0; $n < $num_req; ++$n) { /* Seed the thing, for versions < 4.2.0 */ mt_srand ((double) microtime() * 10000000); $randval = mt_rand(); /* Use the random value to 'pick' an entry from the array */ /* Count the number of times that the entry is picked */ ++$index[$randval % $count]; } /* Loop through the array */ for ($n = 0; $n < $count; ++$n, next($array)) { /* When we get to an entry that has been picked Put the entry into an array for output Don't forget to decrease the counter */ while ($index[$n]) { $out[] = key ($array); --$index[$n]; } } /* Return a string if only on random key was asked for, otherwise return an array */ return ($num_req == 1) ? $out[0] : $out ; } ?>
