Confused between array and objects in Laravel

Question

I\'m learning Laravel and it uses OOPS concepts. Now I\'m finding it hard to understand the real difference between array and objects. I actually know what an array and obje

Answer 1

I think I know the source of your problem, as I've been having to work around it. If you are using the arrow notation on a model object and there is no record in the relationship, then you'll get the "non-object" error. For example, if you have the line

$student->school->school_name

and a given $student doesn't have a school object, you'll get the non-object error. I typically add checks for empty($student->school) or empty($student->school_id) or the like to avoid this when I run into it (or heaven forbid forsee the problem when doing my initial coding pass).

EDIT: So, to clarify, Laravel doesn't say "oh, there's a relationship there, so school is an object which happens to be empty, so I'll return null for school_name", it says "there's no school, so ->school_name is an invalid call to an object property"

Answer 2

Actually the Collection class is a wrapper object which returns a collection of objects. For example, if you have a Model for example, User then you may use it in various ways, to get all records you may use User::all() and to get a single record you may use User::find(1) and there are other ways as well.

If you use all(), get() methods then you'll get a collection object, it means a collection of User models when you use these methods on User model and remember all() and get() always returns a collection of models even if there is only one model in it, so check this examaple:

$users = User::all(); // returns a collection

You may use first() method of Collection object like this:

$users = User::all();
$users->first();

Or directly just:

$user = User::first();

You may also use last to get the last item/model from the collection. You may also use get() like this:

$users = User::all();
$users = User::get(0) // to get first item/model
$users = User::get(1) // to get second item/model

You may also use a loop like this:

$users = User::get(); // same as all
// pass the collection to the view
return View::make('users.index')->with('users', $users);

Now in your views/users/index.blade.php view you may use a loop like this:

@foreach($users as $user)
    {{ $user->username }}<br />
    {{ $user->email }}<br />
@endforeach

It's important to knoe that, all() and get() methods returns a collection and first() and find(id) returns a single model object, so if you have a single model then you may directly use it like this:

$user = user::find(1); // 1 is id for example
return View::make('users.index')->with('user', $user);

In your view you may use:

{{ $user->email }}

You may use an object using -> for example $user->name and an array using $user['name'] but in this case you may use both syntax because Laravel's Eloquent/Model implements ArrayAccess (along with others) interface so every model that extends Eloquent could be used using both array and object syntax to access properties. So, following is possible:

$user = User::where('username', 'me')->get();
return View::make('users.index')->with('user', $user);

In the view you may use:

{{ $user->name }}
{{ $user['name'] }}

For better understanding of the Collection class and it's methods check the source code, you may find it at vendor/laravel/framework/src/Illuminate/Database/Eloquent/Collection.php of your local installation and it extends Illuminate/Support/Collection.php class. Check both classes. You may also read this article, it'll help you more.