Encapsulation issues

Question

I have a tiny issues.

I have 3 classes:

Class Animal {
    public $dog;
    function __construct() {
        $this->dog = new Dog();
    }
}
Class Dog {
    public $scream;
    function __construct() {
        $this->scream = new Scream();
    }
}
Class Scream {
    public $scream;
    function __construct() {
    }
    public haaa(){
       return 'hello World';
    }
}

I'm trying to get haaa() function.. with

 $animal = new Animal();
 $animal->haaa();

If the function haaa() is into the Dog class.. it works fine.. Is it possible that we have a limit of deep encapsulation?

Thank you!

Answer 1

Based on your example it would be:

$animal->dog->haaa();

However, it might be best to change the design so that Dog extends Animal :

class Dog extends Animal {
  public function scream(){
    // do stuff
  }
}

$dog = new Dog();
$dog->scream();

That's more semantic, since dogs belong to the animal "kingdom".