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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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.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.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.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.
Decoratorパターンはオブジェクトに追加の
責務を動的に付与する。デコレータは、サブ
クラス化の代替となる、柔軟な機能拡張手段
を備えている。
Decorator
パターンの定義
デコレータは、装飾するコン
ポーネントと同じインタフェー
スや抽象クラスを実装します。
methodA()
methodB()
//
他のメソッド
ConcreteComponent
コンポーネント
methodA()
methodB()
//
他のメソッド
Component
ConcreteDecorator
は、装飾するオブジェクト
（
Decorator
がラップする
Component
）のインスタン
ス変数を（
Decorator
クラス
から）継承します。
デコレータは新しいメソッドを追加できます。しかし一般
に、新しい振る舞いは、コンポーネントの既存メソッドの前
または後に計算を行って追加します。
各デコレータはコンポーネン
トを持ちます（ラップします、
HAS-A
関係）。つまり、デコ
レータはコンポーネントへの参
照を保持するインスタンス変数
を持つのです。
ConcreteComponent
オブジェクトには新しい
振る舞いが動的に追加さ
れます。このオブジェク
トは
Component
を拡張
します。
まず、
Decorator
パターンの定義を見てみましょう。
この定義は
Decorator
パターンの役割を示しますが、このパターンを自分の
実装に適用する方法についてははっきりしません。以下のクラス図を見てみま
しょう。この図を見るともう少しはっきりします（次のページでは、飲み物の ...
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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.