php oop traversing the parent::child relationship

my actual code is complex so here is a simple but relevant illustration:

class base {

  var $child1;
  var $child2;

  function xcv() {
    $this->child1 = new objChild1();
    $this->child2 = new objChild2();
  }
}

class objChild1 {
  var $fruit = "apple开发者_开发技巧";
}

class objChild2 {
  function getChild1Fruit() {
    echo parent::child1->fruit;
  }
}

fairly straight forward but what if objGrandchild1 wants to call child2 etc... is it like parent::parent::child1->fruit?

any tips in this area would be appreciated

===== EDIT ===== Sorry I just realised that parent belongs to the use of extend so probably nothing to do with it

---

You got it right in the edit you made. An object has no realisation of the object that's being used in. You could get this reference through a parameter, though.

class base {

  var $child1;
  var $child2;

  function xcv() {
    $this->child1 = new objChild1();
    $this->child2 = new objChild2($this);
  }
}

class objChild1 {
  var $fruit = "apple";
}

class objChild2 {
  objChild2($parent) {
    $this->parent = $parent;
  }
  function getChild1Fruit() {
    echo $this->parent->child1->fruit;
  }
}