檢查選單項
public class menuitem
public string getname()
public string getdescription()
public boolean isvegetarian()
public double getprice()
}
lou和mel的選單實現
public class pancakehousemenu
public void additem(string name,string description,boolean vegetarian,double price)
public arraylist getmenuitems()
}
public class dinermenu
public void additem(string name,string description,boolean vegetarian,double price)else
} public menuitem getmenuitems()
}
定義迭代器介面
public inte***ce iterator餐廳實現迭代器介面
public class dinermenuiterator implements iterator
public boolean hasnext() else
} public object next()
}
煎餅店實現迭代器介面
public class pancakehouseiterator implements iterator
public boolean hasnext() else
} public object next()
}
用迭代器改寫餐廳選單
public class dinermenu
public void additem(string name,string description,boolean vegetarian,double price)else
} public iterator createiterator()
}
用迭代器改寫煎餅選單
public class pancakehousemenu
public pancakehousemenu(arraylistpancakeitems)
public void additem(string name,string description,boolean vegetarian,double price)
public iterator createiterator()
}
女招待的實現**
public class waitress
public void printmenu()
private void printmenu(iterator iterator)
} }
測試迭代器的**
public class menutestdrive
}
輸出結果：
menu
-----------
breakfast
k&b's pancake breakfast,
2.99,
pancakes with scrambled eggs, and toast,
regular pancake breakfast,
2.99,
pancakes with fried eggs, sausage,
blueberry pancakes,
2.99,
pancakes made with fresh blueberries,
waffles,
2.99,
waffles, with your choice of blueberries or strawberries,
lunch
vegetarian blt,
2.99,
(fakin') bacon with lettuce & tomato on whole wheat,
blt,
2.99,
bacon with lettuce & tomato on whole wheat,
soup of the day,
3.29,
soup of the day ,with a side of potato salad,
hotdog,
3.05,
a hot dog , with saurkraut , relish , onions , topped with cheese,
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