Headfirst design mode C + + implementation--iterator (Iterator) Improved version

Iterator.h

1 #ifndef _iterator_h_2 #define_iterator_h_3 4 classIterator {5  Public:6     Virtual BOOLHas_next () =0;7     Virtual void*next () =0; 8 };9 #endif

Menu.h

1 #ifndef _menu_h_ 2 #define _menu_h_34class  MENU {5public: 6     Virtual 0 ; 7     virtual ~Menu () {}; 8 }; 9 #endif

Diner_menu.h

1 #ifndef _diner_menu_h_2 #define_diner_menu_h_3 4#include"menu_item.h"5#include"Iterator.h"6#include <vector>7#include"menu.h"8 9 classDinermenu: PublicMenu {Ten  Public: One     voidAdd_item (ConstSTD::string&name, A                   ConstSTD::string&description, -                   BOOLVegetarian, -                   DoublePrice ) { the Menu_items.push_back (MenuItem (name, description, Vegetarian, price)); -     } -  -Dinermenu (): Iterator (* This ) { +Add_item ("Diner Name_1","descrption_1",true,4.5); -Add_item ("Diner name_2","descrption_2",true,6.2); +Add_item ("Diner Name_3","Descrption_3",false,3.5); A     } at      -Iterator *Get_iterator () { -         return&iterator; -     } - Private: -     class_iterator: PublicIterator { in     Private: -Dinermenu &menu; to         intPos; +      Public: -_iterator (Dinermenu &_menu): POS (0), menu (_menu) {} the         BOOLHas_next () {returnPOS <menu.menu_items.size ();} *         void*Next () { $             return& (menu.menu_items[pos++]);Panax Notoginseng         } - } iterator; the   +Std::vector<menuitem>Menu_items; A }; the #endif

Pancake_house_menu.h

1 #ifndef _pancake_house_menu_h_2 #define_pancake_house_menu_h_3 4#include"menu_item.h"5#include"Iterator.h"6#include"menu.h"7 8 classPancakehousemenu: PublicMenu {9  Public:Ten     voidAdd_item (ConstSTD::string&name, One                   ConstSTD::string&description, A                   BOOLVegetarian, -                   DoublePrice ) { -         if(Item_num <Max_items) { themenu_items[item_num++] =NewMenuItem (name, description, vegetarian, price); -         } -     } -      +Pancakehousemenu (): Item_num (0), Iterator (* This) { -Add_item ("Name_1","descrption_1",true,4.5); +Add_item ("name_2","descrption_2",true,6.2); AAdd_item ("Name_3","Descrption_3",false,3.5); at     } -      -~Pancakehousemenu () { -          for(inti =0; i < Item_num; i++ ) { -             DeleteMenu_items[i]; -         } in     } -   toIterator *Get_iterator () { +         return&iterator; -     } the      * Private: $     class_iterator: PublicIterator {Panax Notoginseng     Private: -Pancakehousemenu &menu; the         intPos; +      Public: A_iterator (Pancakehousemenu &_menu): POS (0), menu (_menu) {} the         BOOLHas_next () {returnPOS <Menu.item_num;} +         void*Next () { -             returnmenu.menu_items[pos++]; $         } $ } iterator; -      -     Const Static intMax_items =6; theMenuItem *Menu_items[max_items]; -     intItem_num;Wuyi }; the #endif

Main.cpp

1#include"pancake_house_menu.h"2#include"diner_menu.h"3#include <iostream>4 5 intMain () {6Menu * menus[] = {NewPancakehousemenu,NewDinermenu}; 7      for(inti =0; I <sizeof(menus)/sizeof(menus[0]); i++ ) {8Iterator *iterator = menus[i]->get_iterator ();9          while(iterator->Has_next ()) {TenMenuItem *menu_item = (MenuItem *) iterator->next (); OneStd::cout << menu_item->get_name () <<" " A<< menu_item->get_description () <<" " -<< Menu_item->is_vegetarian () <<" " -<< Menu_item->get_price () <<Std::endl; the         }  -         DeleteMenus[i]; -     } -}

Headfirst design mode C + + implementation--iterator (Iterator) Improved version