Online PHP editor | refs for iir32

<?php class TopLevel { public $arg; public function __construct(string $arg) { printf("Top level: %s\n", $arg); $this->arg = $arg; } } class MidLevel extends TopLevel { public function __construct(string $arg) { printf("Mid level: %s\n", $arg); parent::__construct($arg); } } class EndLevel extends MidLevel { public function __construct(string $arg) { printf("End level: %s\n", $arg); TopLevel::__construct($arg); } } $mid = new MidLevel('mid'); var_dump($mid->arg); echo "---\n"; $end = new EndLevel('end'); var_dump($end->arg);