Dump don't working - php

Question

I have problem when trying to dump some values, but issue is that when I use dump, it don't show any error message and don't dump any value. I have installed symfony/var-dumper.
Source code
<?php
namespace App\Controller;
use App\Form\UserType;
use App\Entity\User;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface;
use Symfony\Component\VarDumper\VarDumper;
class RegistrationController extends Controller
{
/**
* #Route("/register", name="user_registration")
*/
public function registerAction(Request $request, UserPasswordEncoderInterface $passwordEncoder)
{
$user = new User();
$form = $this->createForm(UserType::class, $user);
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$password = $passwordEncoder->encodePassword($user, $user->getPlainPassword());
$user->setPassword($password);
dump($user);
$entityManager = $this->getDoctrine()->getManager();
$entityManager->persist($user);
$entityManager->flush();
return $this->redirectToRoute('number', array('slug' => 1500, 'dump' => $user));
} else {
return $this->render(
'registration/register.html.twig',
array('form' => $form->createView())
);
}
}
}

Answer 1

Add exit; after dump() or check the debug tab in profiler.
It is not visible because you have a redirect response.

Answer 2

If you are using the rest of the framework (as appears to be from the use of Controller), you'll find it linked from the debug-toolbar. However, as you are doing a redirect, the page that you end up on isn't the same request as the dump was made.
If you go into the debug profiler, and click the 'Last 10' button (near the top-left), you will see the previous pages. It's very likely that the 2nd one down will have the 'dump' section linked from the left hand column, and you'll be able to check the output from there.