<?php

class foo
{
    function something()
    {
        echo __CLASS__ . " something\n";
        $this->somethingElse();
    }
    function somethingElse()
    {
        echo __CLASS__ . " somethingElse\n";
    }
}
class foobar extends foo
{
    function somethingElse()
    {
        echo __CLASS__ . " somethingElse\n";
    }
}
$foo = new foobar();
$foo->something();