in_arrayPHP ManualPrevNextin_arrayin_array -- Return true if a value exists in an arrayDescriptionbool in_array(mixed needle, array haystack); Searches haystack for needle and returns true if it is found in the array, false otherwise. Example 1. in_array() example 1  2 $os = array ("Mac", "NT", "Irix", "Linux"); 3 if (in_array ("Irix", $os)) 4  print "Got Irix"; 5  Note: This function was added in PHP 4.0. PrevHomeNextextractUpkey