June 2022
Beginner to intermediate
672 pages
17h 23m
Japanese
Content preview from Head Firstデザインパターン 第2版 ―頭とからだで覚えるデザインパターンの基本
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以下は作り直したクラス構造全体です。いろいろなカモが
Duck
クラスを拡張
し、飛ぶ振る舞いが
FlyBehavior
を実装し、鳴く振る舞いが
QuackBehavior
を実装
するなど、必要なものはすべて揃っています。
物事を少し異なった方法で表していることにも注目しましょう。ここではカモ
の振る舞いを一連の振る舞いと考えるのではなく、一連のアルゴリズムと考えて
います。
SimUDuck
の設計では、アルゴリズムとはカモの実行すること（さまざ
まな方法で鳴いたり飛んだりすること）を表しています。ですが、州ごとの州売
上税を計算する方法を実装するクラス群にも同じテクニックを簡単に使うことが
できます。
クラス間の関係に注目してください。実際にペンを握って、
IS-A
（〜である）、
HAS-A
（〜を持つ）、
IMPLEMENTS
（実装する）といった適切な関係をクラス
図の矢印に書き込んでみましょう。
カプセル化された振る舞いの全体像
これまでカモシミュレータの設計を細かく検討してきたので、ここでは視野を広
げて全体像を見てみましょう。
swim()
display
()
performQuack()
performFly()
setFlyBehavior()
setQuackBehavior()
//
カモに関する他のメソッド
Duck
FlyBehavior flyBehavior
QuackBehavior quackBe
havior
<<interface>>
FlyBehavior
fly()
fly() {
//
カモの飛行を実装
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.