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   ";    }}class tomato_vegetable extends vegetables02{    public function go_vegetable()    {        echo "我是西红柿，我是西红柿，既是水果，也是蔬菜。"."
";    }}function change($obj){    if($obj instanceof vegetables02)    {        $obj->go_vegetable();    }    else    {        echo "输入的参数不是vegetables02的类型."."
";    }}echo "实例化potapo:";change(new potato_vegetable());echo "
   
";echo "实例化tomato:";change(new tomato_vegetable());echo "
";//interface接口实现多态性interface go_vegetables{    public function go_vegetables();}class potato_v implements go_vegetables{    public function go_vegetables()    {        echo "我说我是土豆，你信不?"."
";    }}class tomato_v implements go_vegetables{    public function go_vegetables()    {        echo "我说我是西红柿，你可以信。"."
";    }}function change_01($obj){    if($obj instanceof go_vegetables)    {        $obj->go_vegetables();    }    else    {        echo "输入的参数不是interface类型"."
";    }}echo "实例化potato:";change_01(new potato_v());echo "
   
";echo "实例化tomato:";change_01(new tomato_v());echo "
   
";