array_count_values

<?

$array = array(0, 0, 1, 0, 1, 2);

$return = array_count_values($array);

print_r($return);

?>

Array
(
    [0] => 3
    [1] => 2
    [2] => 1
)

<?

$array = array("a", "a", "b", "a", "b", "c");

$return = array_count_values($array);

print_r($return);

?>

Array
(
    [a] => 3
    [b] => 2
    [c] => 1
)