Online PHP editor | output for mvggu

<?php class World { static $id = 0; protected $uid; protected $worldName; const type = 'world'; public function __construct( $worldName ) { $this->setUID(); $this->worldName = $worldName; } private function setUID() { $this->uid = self::$id++; } public function whoIsPerson( Person $person ) { $personUID = $person->getUID(); if( $personUID === 0 && $this->worldName === 'Rapture' ) return $this->personIDMessage( $personUID, $this->worldName, 'Jack' ); elseif( $personUID === 0 && $this->worldName === 'Columbia' ) return $this->personIDMessage( $personUID, $this->worldName, 'Elizabeth' ); else return 'Unknown Person'; } private function personIDMessage( $id, $world, $name) { return "Person $id in world $world is $name \n"; } } class Person { static $id = 0; protected $uid; public function __construct() { $this->setUID(); } private function setUID() { $this->uid = self::$id++; } public function getUID() { return $this->uid; } } $person1 = new Person(); $world1 = new World('Rapture'); echo $world1->whoIsPerson( $person1 ); $world2 = new World('Columbia'); echo $world2->whoIsPerson( $person1 );