php面向对象 小题记

class aa
{
function m1()
  { 
   echo "m1 runned in aa"."<br/>";

$this->m2();
  }

function m2()
  { 
   echo "m2 runned in aa"."<br/>";

  }

}

class bb extends aa
{
function m2()
  { 
   echo "m2 runned in bb"."<br/>";

  }



}


$a=new bb();

$a->m1();

请问？输出结果是什么：
















是：
m1 runned in aa
m2 runned in bb