Online PHP editor | refs for mUjjl

@ 2014-03-24T02:21:33Z

<?php
// given:
$undef = "0\0b";
//unset($undef);
$null = NULL;
$false = FALSE;
$true = TRUE;


// these operations:
var_dump(isset($undef));
var_dump(empty($undef));
var_dump(array_key_exists('undef', $GLOBALS)); // "defined" below