class Parent
{
  protected $_property;
  protected $_anotherP;

  public function __construct($var)
  {
    $this->_property = $var;
    $this->someMethod();  #Sets $_anotherP
  }

  protected function someMethod()
  ...
}

class Child extends Parent
{
  protected $parent;

  public function __construct($parent)
  {
    $this->parent = $parent;
  }

  private function myMethod()
  {
    return $this->parent->_anotherP;  #Note this line
  }
}

class MyParent {
    protected $data;
    public function __construct() {
        $this->someMethodInTheParentClass();
    }
    protected function someMethodInTheParentClass() {
        $this->data = 123456;
    }
}

class Child extends MyParent {
    public function __construct() {
        parent::__construct();
    }
    public function getData() {
        return $this->data; // will return the $data property
                            // that's defined in the MyParent class
    }
}

$a = new Child();
var_dump($a->getData());

int 123456

class child {

    public parentObject;

    public function __construct($parentObject) {
        $this->parentObject = $parentObject;
    }

}

public function print_name() {
    echo $this->parentObject->name;
}

class Child extends Parent
{
  private function myMethod()
  {
    return $this->_anotherP;
  }
}