(PHP 4 >= 4.0.5)
array_search -- Searches the array for a given value and returns the corresponding key if successfulmixed array_search
(mixed needle, array haystack [, bool strict])
Searches haystack for needle and returns the key if it is found in the array, FALSE otherwise.
If the optional third parameter strict is set to TRUE then the array_search() will also check the types of the needle in the haystack.
See also in_array().