有各種各樣的鴨子（醬鴨、板鴨、黑頭鴨、野鴨、鹽水鴨...），特徵是Quack（嘎嘎叫），Swim（遊水）。於是定義的一個SuperDuck（父類），裡面有方法Quack、Swim、Display顯示！子類比如黑頭鴨、RedHeadDuck，重寫Display方法！ But Now We need the ducks to Fly!How to do?（鴨子要可以飛，怎麼辦？） I Just need to add a fly() method in the SuperDuck(父類),then all the ducks will inherit it.Now's my time to really show my true OO genius!(我真是個OO的天才啊，哈哈！) They just give a demo and there were rubber duckies flying around the screen!Was this idea of a joke?
(他們只不過做了一個讓好多橡皮的鴨子滿螢幕飛的示範！這是在開玩笑嗎？） 不是所有的鴨子都能飛的呀！！！ Thinks about inheritance(考慮一下繼承)我可以在RubberDuck（橡皮鴨）中重寫Fly的方法。 But then what happens when wu add wooden decoy ducks（木頭鴨），它既不能Quack叫，也不能Fly。在木頭鴨重寫Quack（）、Fly（）？？？？ How about a interface？I could take the fly() out of the SuperDuck(父類)，and make a flyable() interface with a fly() method. That way,only the ducks that are supposed to fly will implement that interface and have a fly() method....and I might as well make a Quackable(嘎嘎),too，since not all the ducks can quack!(介面怎麼樣？我可以把Fly從父類中剝離出來，變成一個介面，如果有鴨子可以飛，那麼這隻鴨子就實現這個介面。 Quack(嘎嘎叫)也是類似的.） That is , like , the dumbest idea you've come up with.Can you say "duplicate code"?If you thought having to override a few methods was bad,How are you gonna feel when you need to make a little change to the flying behavior... in all 48 of the flying Duck subclass?!（現在你可以說copy代碼。那麼我們如果對flying 有一個小小的改變怎麼樣？所有48個用到這個介面的子類都要改變一下，Copy48份？？？？？） How we can do next？？？到底該怎麼辦？Please be with <<Head First Design pattern>>!
