3v4l.org

run code in 300+ PHP versions simultaneously
<?php class foo { public $baz = 'bar'; function __get($name) { if ($name == 'bar') return $this->baz; } } for($i=0; $i<10000;$i++) $o = new foo; var_dump($o->bar); var_dump(isset($o->bar));

preferences:
35.51 ms | 402 KiB | 5 Q