How to call an ancestor class variable?

Question

PHP

There are two classes a and b how to get variables from class b if they are reassigned?

class a {
  public $data;
}

class b extends a {
  public $data;
  public function get_data() {
    Как вызвать $data класса a?
  }
}

This is how it doesn't work

class a {
  public $data;
}

class b extends a {
  public $data;
  public function get_data() {
    parent::data;
  }
}

Found a crutch on the Internet

class a {
  public $data;
  public function data() {
    return $this->data;
  }
}

class b extends a {
  public $data;
  public function get_data() {
    parent::data();
  }
}

Is there a solution without a crutch?
[ Solution ]
Use different variable names, unfortunately there is no normal variable redirection in puff yet.

Answer 1

you violated the basic principle of DRY (do not repeat yourself). this means that you don't need to define a variable with the same name and access in the child class if it exists in the parent(s)

Answer 2

parent::data;
Why are you calling like that? It's not a constant.
parent::$data;