(PHP 4 >= 4.0.5, PHP 5)
array_search — Searches the array for a given value and returns the corresponding key if successful
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
<?php
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array); // $key = 1;
?>
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().