note 11383 modified in Array Functions by jmcastagnetto

[Editor's note: another option is to use other array functions, i.e.: if ( in_array($someindex, array_keys($somearray)) ) instead of the comparison to NULL] Ever had a dynamically generated associative array, and wanted an easy way to figure out if an index exists or not? Here's my simple solution: // Sample Array $somearray = array(0 => "Hi", 1 => 14, 2 => "Testing", 4 => "Bob"); // Does $someindex exist in $somearray? if (gettype($somearray[$someindex])!="NULL") { // It does exist } else { // It doesn't exist } This also works with multi-dimensional arrays: $userarray = array{ 0 => array("Name" => "Bob", "PW" => "lAm24"), 1 => array("Name" => "John", "PW" => "Iam24andTHE1"), 3 => array("Name" => "Joe", "PW" => "blahhalb")); // (Not real PW data, just a sample!) // Does the user ID exist? if (gettype($userarray[$userid])!="NULL") { // The User ID exists } else { // The User ID doesn't exist } http://www.php.net/manual/array-functions.php