Before continuing, make sure you've read the Installation chapter and can access your new Symfony app in the browser.
Suppose you want to create a page - /lucky/number - that generates a lucky (well, random) number and prints it. To do that, create a "Controller class" and a "controller" method inside of it that will be executed when someone goes to /lucky/number
// src/AppBundle/Controller/LuckyController.php namespace AppBundle\Controller; use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route; use Symfony\Component\HttpFoundation\Response; class LuckyController { /** * @Route("/lucky/number") */ public function numberAction() { $number = rand(0, 100); return new Response( '<html><body>Lucky number: '.$number.'</body></html>' ); } }