<?php

class A {
  private $foo="a";
  protected $bar="a";
  function getAstuff() {
    return $this->foo.'/'.$this->bar;
  }
}

class B extends A {
  private $foo="b";
  protected $bar="b";
  function getBstuff() {
    return $this->foo.'/'.$this->bar;
  }
}

$b=new B();
echo 'getBstuff: '.$b->getBstuff()."\ngetAstuff: ".$b->getAstuff()."\n";

/*
Output:
getBstuff: b/b
getAstuff: a/b

As you see, methods defined in class A use the private vars of class A
even when used on an instance of child class B. 
Protected attributes however are overridden just like private ones. 
Notice that I do use overridden properties here. 
You could not access $foo from B if it was not overwritten there. 

*/