extending static methods in php

Question

class Foo {
  public static function foobar() {
    self::whereami();
  }

  protected static function whereami() {
    echo 'foo';
  }
}

class Bar extends Foo {
  protected static function whereami() {
    echo 'bar';
  } 
}

Foo::foobar();
Bar::foobar();

expected result foobar actual result foofoo

to make matters worse, the server is restricted to php 5.2

Answer 1

All you need is a one-word change!

The problem is in the way you call whereami(), instead of self:: you should use static::. So class Foo should look like this:

class Foo {
  public static function foobar() {
    static::whereami();
  }
  protected static function whereami() {
    echo 'foo';
  }
}

In another word, 'static' actually makes the call to whereami() dynamic :) - it depends on what class the call is in.