PHP array_search function

array_search

(PHP 4 >= 4.0.5, PHP 5)

array_search -- Searches the array for a given value and returns the corresponding key if successfulDescriptionmixed 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.

Note:
If needle is a string, the comparison is done
in a case-sensitive manner.

Note:
Prior to PHP 4.2.0, array_search() returns
NULL on failure instead of FALSE.

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.

If needle is found in
haystack more than once, the first matching key
is returned. To return the keys for all matching values, use
array_keys() with the optional
search_value parameter instead.

Example 1. array_search() example

$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array); // $key = 1;

Warning

This function may
return Boolean FALSE, but may also return a non-Boolean value which
evaluates to FALSE, such as 0 or
"". Please read the section on Booleans for more
information. Use the ===
operator for testing the return value of this
function.

See also array_keys(),
array_values(),
array_key_exists(), and
in_array().