note 121592 deleted from function.array-key-exists by crell

Note Submitter: falundir at gmail dot com ---- This function will return NULL when second argument is not an array. So it will bite you when using it like that: <?php $not_an_array = null; if (array_key_exists($key, $not_an_array) === false) { // the array doesn't have the key return; } // happily proceed - surely the array does have the key (BUT IT DOESN'T!) ?> That's because the condition null === false fails. Instead you should use: <?php if (array_key_exists($key, $not_an_array) == false) { return; } // or if (!array_key_exists($key, $not_an_array)) { return; } // or if (is_array($not_an_array) === false || array_key_exists($key, $not_an_array) === false) { return; } ?>