注意：未定义的偏移量：9 [重复]

Question

This question already has an answer here:

• Reference - What does this error mean in PHP? 34 answers

I'm working with symfony and php and I'm new in this. I want to echo all the user's cars.

class UserController extends Controller
{   
    public function indexAction($uname)
    {
        $cars = new cars();
        $user = new user();
        $models = new models();
        $brands = new brands();
        $a = 1;

        $em = $this -> getDoctrine() -> getEntityManager();
        $id = $em -> getRepository("OBCarsTest1Bundle:user") ->findOneByuname($uname);
        array ($UserCars = $em -> getRepository("OBCarsTest1Bundle:cars") ->findByidUser($id));
        //$ModelId = $em -> getRepository("OBCarsTest1Bundle:models")->findById($UserCars);
        //$BrandsId = $em -> getRepository("OBCarsTest1Bundle:brands")->findOneById($ModelId);

        while($UserCars[$a]->getId() != Null)
        {
            if(! isset($UserCars[$a]))
            {
                $UserCars[$a] = Null;
            }
            //i want to see all the cars of the users
            echo ('Created user :  '.$UserCars[$a]->getName());
            //return new Response('Created user :  '.$UserCars[$a]->getId());
            $a++;
        }

        return new Response('ma akal');

        //return $this->render('OBCarsTest1Bundle:Default:index.html.twig', array('UserCars' => $UserCars));
    }

Now my code looks like this (before making any changes) but i'm having an error:

Notice: Undefined property: OBCarsTest1Bundle\Entity\cars::$getName

I searched for the problem and tried to fix it and change in the code but i got the same result.

class UserController extends Controller
{   
    public function indexAction($uname)
    {
        $cars = new cars();
        $user = new user();
        $models = new models();
        $brands = new brands();
        $a = 0;

        $em = $this -> getDoctrine();
        $id = $em -> getRepository("OBCarsTest1Bundle:user") ->findOneByuname($uname);
        $UserCars = $em -> getRepository("OBCarsTest1Bundle:cars") ->findByidUser($id);
        //$ModelId = $em -> getRepository("OBCarsTest1Bundle:models")->findById($UserCars);
        //$BrandsId = $em -> getRepository("OBCarsTest1Bundle:brands")->findOneById($ModelId);

        foreach($UserCars as $car)
        {
            echo "$car->getName() <br>";
        }


        return new Response('ma akal');

        //return $this->render('OBCarsTest1Bundle:Default:index.html.twig', array('UserCars' => $UserCars));
    }

</div>

Answer 1

There are two problems here:

1. Array indices are 0-based and you use $a = 1; so you are probably missing out on the first element;

2. You should not loop over an array using a while loop like that as you will always run into problems / errors / warnings when there are no more elements, this loop ends with a warning by definition:

   while($UserCars[$a]->getId() != Null)
   
   Instead you should use a foreach loop to loop over every element:

   foreach ($UserCars as $UserCar) { // not sure if you need this, I would guess you don't: if ($UserCar->getId() != Null) { ...