Online PHP editor | output for qQ1s1

<?php class A { public array $foo = ['baz' => 10]; public int $bar { get => $this->foo['baz']; set { $this->foo['baz'] = $value; //$this->bar = $value; } } public function __sleep() { return ['foo']; //array_keys(get_object_vars($this)); } } $a = new A; $a->bar = 20; var_dump(unserialize(serialize($a))->bar);