Online PHP editor | refs for ngRNN

<?php echo "\$a unset\n isset: "; var_export(isset($a)); echo "\n value: "; var_export($a); echo "\n\n"; $a = null; echo "\$a is null\n isset: "; var_export(isset($a)); echo "\n value: "; var_export($a); echo "\n\n"; $a = (object) null; echo "\$a is object\n isset: "; var_export(isset($a)); echo "\n value: "; var_export($a); echo "\n\n"; echo "\$a->b unset:\n isset: "; var_export(isset($a->b)); echo "\n value: "; var_export($a->b); echo "\n\n"; $a->b = null; echo "\$a->b is null:\n isset: "; var_export(isset($a->b)); echo "\n value: "; var_export($a->b); echo "\n\n"; echo "\$a->b is null, what's \$a?\n isset: "; var_export(isset($a)); echo "\n value: "; var_export($a); echo "\n";