探讨方法的重写(覆载)详解

<?php
 class cart{
  public function cart(){
   echo "正在调用cart()<br />";
  }
  public function dosomething(){
   echo "正在调用dosomethimg()<br />";
  }
 }
 class named_cart extends cart{
  function named_cart(){
   echo "正在调用named_cart()<br />";
  }
  function dosomething(){
   echo "正在调用named_cart::dosomething()<br />";
  }
 }
$mycart=new cart();
$mycart->dosomething();
$mynamed_cart=new named_cart();
$mynamed_cart->dosomething();
?>