... PHP 4 >= 4.0.0) in_array -- Return TRUE if a value exists in an array . bool in_array ( mixed needle, array haystack [, bool strict]) . Searches haystack for needle and returns TRUE if it is found in the array, FALSE otherwise. ... Example 1. in_array() example . ... Example 2. in_array() with strict example . php $a = array('1.10', 12.4, 1.13); if (in_array('12.4', $a, TRUE)) echo "'12.4' found with strict check\n"; if (in_array(1.13, $a, TRUE)) echo "1.13 found with strict check\n"; ?> ...