Order of cascading constructor arguments

[NotionCommotion]

Is there any order variables injected in the constructor and then the parent's constructor more typically used than the other or considered best practice?  I believe the last example is less than desired, but feel the first two both have their merits.

EDIT.  I guess if one every uses defaults in a constructor, then the first option is best.

class ParentClass extends ChildClass
{
    public $obj1;
    public function __construct(Class1 $obj1, Class2 $obj2, Class3 $obj3) {
        $this->obj1=$obj1;
        parent::__construct($obj2, $obj3);
    }
}

class ParentClass extends ChildClass
{
    public $obj3;
    public function __construct(Class1 $obj1, Class2 $obj2, Class3 $obj3) {
        $this->obj3=$obj3;
        parent::__construct($obj1, $obj2);
    }
}

class ParentClass extends ChildClass
{
    public $obj2;
    public function __construct(Class1 $obj1, Class2 $obj2, Class3 $obj3) {
        $this->obj2=$obj2;
        parent::__construct($obj1, $obj3);
    }
}

 

 

[requinix]

It doesn't matter, and there's no particular best practice. Additional parameters often go last but only because that's how it often ends up - optional parameters will force some arrangements, and otherwise general sensibility is more important.

But it is good practice to call the parent constructor as early as possible - ideally as the first statement in the constructor. That ensures the object is set up correctly (as far as the parent class is concerned) before anything else happens.