# Swift Design Pattern 讀書會
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### Chapter 2: How to Read a Class Diagram
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開始之前...
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分享：
你的開發流程是怎樣？
從拿到需求到 deploy 的過程
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上集提要：
Design patterns aren’t concrete implementations, but rather, they are a starting point for writing code.
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什麼是 class diagram ？
- UML 一種
- 描述類別之間的關係
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## 為什麼要用 UML？
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為什麼要用 UML？
我的想法：
自然語言很囉唆 ＋ 容易引起歧義
UML 一目瞭然
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類別之間的關係可以有什麼關係?
1. ia-a
2. has-a
- association 結合 (has-a)
- aggregation 聚合 / composition 組合 (contains-a)
3. implementation
4. dependency
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## 1. ia-a
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## 2. has-a (association)
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## 3. implementation
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## 4. dependency
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## UML Generator
APP:
https://www.visual-paradigm.com/tw/download/community.jsp
線上:
https://online.visual-paradigm.com/tw/
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End
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