Online PHP editor | output for GdgGo

<?php class foo { private $data; private $relations; public function __set($name, $value) { $this->data[$name] = $value; } public function __get($name) { if(isset($this->data[$name])){ return $this->data[$name]; } } public function __construct() { $this->data = ['foo' => 'test', 'body' => 'content']; } public function test() { $function = debug_backtrace()[1]['function']; $this->data[$function] = ['a' =>'aa', 'b' =>'bb']; return $this; } } class bar extends foo{ public function aa(){ return $this->test(); } } $bar = new bar(); $bar->foo; $bar->aa()->a;