php多态

<?php/**2014-3-23多态(同一类型，不同结果)重载算是多态的一中*/interface employee{public function working();}class teacher implements employee{public function working(){echo '教书';}}class coder implements employee{public function working(){echo '敲代码';}}function doprint(employee $i){$i=$i->working();}$a=new teacher();$b=new coder();doprint($a);doprint($b);?>