The document discusses code refactoring, which involves restructuring existing code without altering its external behavior. It outlines various advantages such as improved expressiveness, readability, maintainability, and extensibility, along with techniques like generalization, extraction, encapsulation, and renaming. The emphasis is on enhancing internal software design to facilitate better management of complex code structures.

1. Code Refactoring
Presented by Steven
Dec. 2016

2. Why
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3. 3

4. 4

5. Fast
Runnable
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6. Fast
Runnable
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7. Spaghetti Code
● program flow is conceptually like a bowl of
spaghetti, i.e. twisted and tangled.
● complex and confusing control structures that are
barely understandable
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8. 8

9. What
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10. ● Code refactoring is the process of restructuring
existing computer code without changing its
external behaviour.
Code Refactoring
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11. 在不改變軟體的外在行為下，改
善既有軟體的內部設計。
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12. 2 Advantages
6 Techniques
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13. Advantages
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14. Expressiveness
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15. Expressiveness
Complexity
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16. Expressiveness
Complexity
Readability
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17. 17

18. Expressiveness
Complexity
Readability
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19. Maintainability
Expressiveness
Complexity
Readability
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20. Maintainability
Expressiveness
Complexity
Readability
Extensibility
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21. Maintainability Extensibility
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22. Techniques
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23. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenaming
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24. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenamingcommon: private / (default) / protected / public
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25. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenamingcreate more general types, e.g., super-classes
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26. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenaming
extract {classes, methods, funcions}
fewer methods → clearer purpose and functionality
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27. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenaming
rename {methods, fields}
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28. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenaming
moving methods between parent/child classes
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29. Generalization ExtractionEncapsulation
Pulling-up Pushing-downRenaming
http://refactoring.com/catalog/index.html29

30. How
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31. Encapsulation 31

32. Encapsulation 32

33. data / field → private
Setter & Getter
Encapsulation 33

34. Generalization 34

35. Generalization 35

36. Generalization 36

37. Generalization 37

38. Generalization 38

39. Renaming 39

40. Renaming 40

41. Conclusion
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42. ● what
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43. ● what
Maintainability
Extensibility
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