Call to a member function getNbr() on array - php

Question

i want to select all users in the database that have the role ROLE_USER only but i get this problm when i call the function they say "Call to a member function getNbr() on null" i think bcoz i use Findby() , bcoz i use the same function in another call and it works great look at the code :
public function indexAction(Request $request)
{
$us = $this->getDoctrine()->getManager();
$locationus = $us->getRepository('AppBundle:Usr')->findBy(
[ 'roles' => ["ROLE_USER"] ]);
echo $nb_us = $locationus->getNbr();
if($authChecker->isGranted(['ROLE_ADMIN']))
{
return $this->render('settingAdmin/profiladmin.html.twig' , array(
'nb_us' => $nb_us,
));
}
and this is the other function in the UserRepository:
class UserRepository extends \Doctrine\ORM\EntityRepository
{
public function getNbr() {
return $this->createQueryBuilder('l')
->select('COUNT(l)')
->getQuery()
->getSingleScalarResult();
}
}

Answer 1

getNbr is method of UserRepository class, so it can be called only for this UserRepository class instance. This method returns total users count.
findBy returns array of entities (in you case all users with role ROLE_USER), not UserRepository class instance, so you can't use getNbr in context of this variable
If you want to get the length of array of entities (in you case all users with role ROLE_USER), just use count function:
echo $nb_us = count($locationus);
if($authChecker->isGranted(['ROLE_ADMIN']))
{
return $this->render('settingAdmin/profiladmin.html.twig' , array(
'nb_us' => $nb_us, 'locationus' => $locationus
));
}

Answer 2

There looks to be quite many things going on in the code there:
1) $us->getRepository('AppBundle:Usr') is probably typoed and should be $us->getRepository('AppBundle:User') instead (?) In general it would be safer to use $us->getRepository(AppBundle\User::class) so that syntax errors can be caught easier/earlier.
2) You are trying to invoke repository method on array with $locationus->getNbr() which is incorrect on multiple accounts (you cannot invoke functions on arrays - and repository methods cannot be invoked from entities either).
3) why is the code using echo?
4) as an additional note (assuming that this is roughly the full intended code), it would make sense to move all the getters & handling inside the if section so that the code will perform better (it doesn't do unnecessary database queries etc when the user doesn't have enough rights to access the view/information).
If I understood the intention correctly, in this case, the second repository function getNbr is superfluous here. If that is intending to just calculate the number of instances returned by the first find:
$locationus = $us->getRepository('AppBundle:User')->findBy(['roles' => ["ROLE_USER"] ]);
$nb_us = count($locationus);
Or alternatively (if you want to use and fix the getNbr repository function) then you don't need the first repository getter. This will require some rewriting of the repository function as well though:
$nb_us = $us->getRepository('AppBundle:User')->getNbr("ROLE_USER");