Online PHP editor | refs for gBT5h

<?php $string = <<<XML <?xml version='1.0'?> <document> <title>Forty What?</title> <from>Joe</from> <to>Jane</to> <body> I know that's the answer -- but what's the question? </body> </document> XML; $xml = simplexml_load_string($string); var_dump( isset($xml->undefined), is_null($xml->undefined), $xml->undefined != null, $xml->undefined !== null );