Overriding static members in derived classes in PHP

Answer 1

You have to re-implment base class method; try with:

class Derived extends Base {
  protected static $c = 'derived';

  public static function getC() {
    return self::$c;
  }
}

As you see, this solution is very useless, because force to re-write all subclassed methods.

The value of self::$c depends only on the class where the method was actually implemented, not the class from which it was called.