Online PHP editor | refs for 90GbJ

@ 2014-03-24T02:17:10Z

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

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