- rand: documentation ( source)
<?php
$code_name_array = array("Vichy negazuotas 0,5 l", "Vichy gazuotas 0,5 l", "Vichy gazuotas 0,5 l");
$code_name_array_random = rand(1, count($code_name_array));
echo $code_name_array[0];
echo $code_name_array_random;
?>