Online PHP editor | output for 2TgJn

<?php class Item { private $notifier; public function __construct(callable $notifier) { $this->notifier = $notifier; } public function setTtl($time) { call_user_func($this->notifier, $time); } } class Pool { private $ttls = []; public function getItem($id) { return new Item(function ($ttl) use ($id) { $this->ttls[$id] = $ttl; }); } public function getTtl($id) { return $this->ttls[$id]; } } $pool = new Pool; $item = $pool->getItem('foo'); $item->setTtl(60); echo $pool->getTtl('foo');