array_rand
(PHP 4, PHP 5)
array_rand — Pick one or more random entries out of an array
Description
mixed array_rand
( array $input
[, int $num_req
] )
array_rand() is rather useful when you want to pick one or more random entries out of an array. It takes an input array and an optional argument num_req which specifies how many entries you want to pick - if not specified, it defaults to 1.
If you are picking only one entry, array_rand() returns the key for a random entry. Otherwise, it returns an array of keys for the random entries. This is done so that you can pick random keys as well as values out of the array.
Note: 由PHP 4.2.0 始,您不需要再使用 srand() 或 mt_srand() 為亂數產生器提供種子,因為這已自動的提供了。
Example#1 array_rand() example
<?php
srand((float) microtime() * 10000000);
$input = array("Neo", "Morpheus", "Trinity", "Cypher", "Tank");
$rand_keys = array_rand($input, 2);
echo $input[$rand_keys[0]] . "\n";
echo $input[$rand_keys[1]] . "\n";
?>
See also shuffle().