如何在面向对象的PHP中将变量从扩展类传递到另一个

Question

I have been trying to change my functions that heavily use global variables into classes. I got into a problem of accessing the variable $totalRows in class Sister, which is a total row count fetched from mysql and passed into the extended class Brother.

Just a pseudo code to get the point across. The real situation is more complicated and prevents me from putting all these into one big class:

class Mother{

  public function __construct($itemPerPage){

     $this->itemPerPage = $itemPerPage;
  }
}

class Brother extends Mother{

    public function __construct($totalRows){

       $this->totalRows = $totalRows;

    }
}

class Sister extends Mother{

    public function renderPager(){

       $totalRows = $this->totalRows;

       $itemPerPage = $this->itemPerPage;

       $totalPages = ceil($totalRows/$itemPerPage);

    }
}

The $totalRows can't be read in Sister because it is not in the main class Mother. Should I just simply pass the $totalRows again in a __construct function in Sister? Is there another way to pass $totalRows from Brother to Sister?

Answer 1

class Brother extends Mother{
  protected $totalRows;
    public function __construct($totalRows){

       $this->totalRows = $totalRows;

    }
}

Working ?