Object Oriented Programming in Swift Ch 0 Encapsulation

1. Object Oriented Programming
in Swift
Ch 0
Sai Li @ Yowoo Tech.
2016/11/18

2. References

3. References
• Agile Software Development: Principles, Patterns,
and Practice ( : )
by Robert C. Martin

4. References
• Agile Software Development: Principles, Patterns,
and Practice ( : )
by Robert C. Martin
• Fundamental Object Oriented Programming
by Hsuan-Tien Lin

5. References
• Agile Software Development: Principles, Patterns,
and Practice ( : )
by Robert C. Martin
• Fundamental Object Oriented Programming
by Hsuan-Tien Lin
•
by Teddy Chen

6. References
• Agile Software Development: Principles, Patterns,
and Practice ( : )
by Robert C. Martin
• Fundamental Object Oriented Programming
by Hsuan-Tien Lin
•
by Teddy Chen
• Essential Object-Oriented Programming
by Josh Ko

7. Language
• Java
• Python
• Swift

8. How to build an
iPhone?

10. System -> Components

11. System -> Components
Divide and Conquer

12. System -> Components
Divide and Conquer
Modularization

13. Good Modules make good System

14. Good Modules make good System
• Easy to debug

15. Good Modules make good System
• Easy to debug
• Easy to maintain/ manage

16. Good Modules make good System
• Easy to debug
• Easy to maintain/ manage
• Easy to modify/ update

17. Good Modules make good System
• Easy to debug
• Easy to maintain/ manage
• Easy to modify/ update
• Easy to reuse

18. Good Modules make good System
• Easy to debug
• Easy to maintain/ manage
• Easy to modify/ update
• Easy to reuse

19. Good Modules make good System
• Easy to debug
• Easy to maintain/ manage
• Easy to modify/ update
• Easy to reuse
Modularization: Save time in the future

20. Save money, save time
No more disposable programs

21. Spaghetti Code

22. Spaghetti Code
Edible is enough

23. Spaghetti Code

24. Spaghetti Code

25. Noodle Oriented
Programming

26. Noodle -> Procedure
• More organized than spaghetti code
• Identify the purpose
• Isolate (modularize)
• Reuse

27. Noodle -> Procedure
• More organized than spaghetti code
• Identify the purpose
• Isolate (modularize)
• Reuse
C language

28. OOP
• Grouped related data

29. OOP
• Use Struct/ Class to generate objects

30. OOP
• Don’t do something on the object
• Let object takes actions

31. OOP
• Don’t do something on the object
• Let object takes actions

32. OOP
• Don’t do something on the object
• Let object takes actions

33. Noodles -> Procedure -> Object

34. • NOP: spaghetti code + (possibly spaghetti) data
Assembly
Noodles -> Procedure -> Object

35. • NOP: spaghetti code + (possibly spaghetti) data
Assembly
• POP: organized code + (possibly organized) data
C, PASCAL
basic modules: procedures
Noodles -> Procedure -> Object

36. • NOP: spaghetti code + (possibly spaghetti) data
Assembly
• POP: organized code + (possibly organized) data
C, PASCAL
basic modules: procedures
• OOP: organized code + organized data (grouped)
Swift, Java, Python
basic modules: Class / Struct
Noodles -> Procedure -> Object

37. OO Levels

38. OO Levels
• OO Analysis:
what the system does

39. OO Levels
• OO Analysis:
what the system does
• needs -> models

40. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering

41. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it

42. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it
• model -> class diagrams

43. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it
• model -> class diagrams
• Design Pattern

44. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it
• model -> class diagrams
• Design Pattern
• OO Programming
how to implement it

45. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it
• model -> class diagrams
• Design Pattern
• OO Programming
how to implement it
• class diagrams -> implementations

46. OO Levels
• OO Analysis:
what the system does
• needs -> models
• Software Engineering
• OO Design:
how the system dose it
• model -> class diagrams
• Design Pattern
• OO Programming
how to implement it
• class diagrams -> implementations
• OOP, this one

47. How to build an
iPhone?

48. Decomposition

49. Decomposition
System

50. Decomposition
System
object
objectobject

51. Decomposition
System
abstraction
object
objectobject

52. Decomposition
System
abstraction
object
objectobject

53. Decomposition
System
abstraction
object
Modeling
objectobject

54. Data Abstraction
Object

55. Data Abstraction
Object
method

56. Data Abstraction
Object
method

57. Data Abstraction
Object
method

58. Data Abstraction
Object
method
Interface

59. Data Abstraction
Object
method
Interface
Implementation

60. Data Abstraction
Abstraction is selective ignorance.
by Andrew Koenig

61. Data Abstraction
Abstraction is selective ignorance.
by Andrew Koenig
Others care about the interface and
ignore the implementation

62. Encapsulation
Access Control: public and private

63. Encapsulation
Access Control: public and private

64. Encapsulation
Access Control: public and private

65. Design by Contract

66. Design by Contract
• Class Invariant

67. Design by Contract
• Class Invariant
• Valid State

68. Design by Contract
• Class Invariant
• Valid State

69. Design by Contract
• Class Invariant
• Valid State
private(set)
private(set)

70. Design by Contract
• Class Invariant
• Valid State
• 1 <= day <= 31
0 <= hour <= 24
private(set)
private(set)

71. Design by Contract
• Preconditions, postconditions

72. Design by Contract
• Preconditions, postconditions
First class invariant ?

73. Design by Contract
• Preconditions, postconditions
First class invariant ?
Constructor

82. Encapsulation

83. • Separate implementation and use
Encapsulation

84. • Separate implementation and use
• Don’t trust other people including you(3 months after)
Encapsulation

85. • Separate implementation and use
• Don’t trust other people including you(3 months after)
• Hide unnecessary details
Encapsulation

86. • Separate implementation and use
• Don’t trust other people including you(3 months after)
• Hide unnecessary details
• One more oz
Encapsulation

87. • Separate implementation and use
• Don’t trust other people including you(3 months after)
• Hide unnecessary details
• One more oz
Encapsulation

88. • Separate implementation and use
• Don’t trust other people including you(3 months after)
• Hide unnecessary details
• One more oz
Think about incorrect use about your class
Encapsulation

89. As a designer,
you should avoid giving the users of your
code too much freedom to do bad and/or
make bugs

92. accessor (getter)

93. accessor (getter)

94. accessor (getter)
mutator (setter)

95. OOP
• Encapsulation: Security
• Inheritance: Reusability
• Polymorphism: Flexibility

96. Q & A
To be continued…

97. References

98. References
• Agile Software Development: Principles, Patterns, and Practice (
: )

99. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming

100. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•

101. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•
• Essential Object-Oriented Programming

102. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•
• Essential Object-Oriented Programming
• images.techtimes.com/data/images/full/11234/tangled-earbuds.jpg

103. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•
• Essential Object-Oriented Programming
• images.techtimes.com/data/images/full/11234/tangled-earbuds.jpg
• spaghetticrunch.com/wp-content/uploads/2014/12/spaghetti-
bolognaise-1.png

104. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•
• Essential Object-Oriented Programming
• images.techtimes.com/data/images/full/11234/tangled-earbuds.jpg
• spaghetticrunch.com/wp-content/uploads/2014/12/spaghetti-
bolognaise-1.png
• upload.wikimedia.org/wikipedia/commons/thumb/e/ea/
Design_by_contract.svg/220px-Design_by_contract.svg.png

105. References
• Agile Software Development: Principles, Patterns, and Practice (
: )
• Fundamental Object Oriented Programming
•
• Essential Object-Oriented Programming
• images.techtimes.com/data/images/full/11234/tangled-earbuds.jpg
• spaghetticrunch.com/wp-content/uploads/2014/12/spaghetti-
bolognaise-1.png
• upload.wikimedia.org/wikipedia/commons/thumb/e/ea/
Design_by_contract.svg/220px-Design_by_contract.svg.png
• www.linuxdigest.org/wp-content/uploads/2012/06/09fig091.gif