An introduction to code refactoring, the process of restructuring existing computer code without changing its external behavior. This keynote will also include common techniques of doing code refactoring, with real-code demonstration.

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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44. 44

45. 45