<?php class a { public static $var; public function a($var) { self::$var = $var; } public function ret() { return self::$var; } } class b extends a { public static $var; } class c extends a { } $a = new a('-a-'); $a2 = new a('-a2-'); $b = new b('-b-'); $c = new c('-c-'); b::$var = 'b'; echo 'A: ' . a::$var; echo 'A2: ' . $a2::$var; echo ', B: ' . b::$var; echo ', C: ' . c::$var;