class Auto { private $aantalDeuren; public function setAantalDeuren($aantal) { $this->aantalDeuren = $aantal; } public function getAantalDeuren() { return $this->aantalDeuren; } } $kleineAuto = new Auto(); $groteAuto = new Auto(); $kleineAuto->setAantalDeuren(3); $groteAuto->setAantalDeuren(5); $groteAuto->setAantalDeuren($kleineAuto->getAantalDeuren() + 2); ?> <!DOCTYPE html> <!-- To change this license header, choose License Headers in Project Properties. To change this template file, choose Tools | Templates and open the template in the editor. --> <html> <head> <meta charset="UTF-8"> <title>Klassen in de praktijk</title> </head>