Get only the array elements with certain keys [duplicate]

Question

Possible Duplicate:
Pattern Match on a Array Key

I need to get all the elements in an array with a specific key pattern. For example in this array:

$items = array(
   "a"         => "1",
   "b"         => "2",
   "special_1" => "3",
   "c"         => "4",
   "special_2" => "5",
   "special_3" => "6",
   "d"         => "7"
);

I would need all elements with a key containing the string special_. These should define a new array:

$special_items = array(
   "special_1" => "3",
   "special_2" => "5",
   "special_3" => "6",
);

Is there a smart method besides a while loop?

Answer 1

How about this?

$special_items = array();

foreach($items as $key => $val) {
    if(substr($key, 0, 8) == 'special_')
        $special_items[$key] = $val;
}