<?php
abstract class A {
protected static $what;
static function change_what($where) {
static::$what = $where;
}
static function show() {
echo static::$what . PHP_EOL;
}
}
class B extends A {
static function change_what($where) {
static::$what = $where;
}
}
class C extends A {
static function change_what($where) {
static::$what = $where;
}
}
B::change_what("b");
C::change_what("c");
B::show();
C::show();