Object Oriented Programming in Swift Ch1 - Inheritance
- 1. Object Oriented Programming in Swift Ch 1: Inheritance Sai Li @ Yowoo Tech. 2016/12/5
- 2. 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
- 3. OOP Encapsulation Inheritance Polymorphism
- 5. Inheritance
- 6. Has-A Has-A: a basic way to reuse variables/methods in other classes
- 7. Has-A Has-A: a basic way to de鍖ne components of a system iPhone has a camera
- 8. Has-A Has-A: a basic mechanism for objects to connect with each other He has 2 friends: Tom and Jerry
- 9. Has-A: most basic design component of OOP
- 10. chi Admin is a user can be implemented via has-a: Everyone has Brokeback Mountain in mind child
- 11. Type A inherit TypeB: TypeA is a (special case of) TypeB TypeSubClass (TypeDerivedClass or ChildClass) inherit TypeSuperClass (TypeBaseClass or ParentClass)
- 12. is-a != has-a
- 13. Uses of Is-A CDAndCassetePlayer is a CassettePlayer
- 14. Uses of Is-A CassettePlayer is a (concrete type of) Player CDPlayer is a (concrete type of) Player
- 15. Uses of Is-A CDplayer is a (update of) CassettePlayer some behaviors changed no as clear as the previous case, but a potential trick in OOP
- 16. Multiple inheritance: Not supported in Swift Swift: single inheritance (Java)
- 18. Diamond Problem
- 19. Is-A is an extended type of - FunPerson is Person who can tell jokes is a more concrete/restricted description of - YoungPerson is Person who is young (is an update of) - NewStaff replaces ExistingStaff
- 21. Over-use of inherit for is-a: 1 class -> 1 instance Usual goal of OOP: one class, many instances
- 22. Is-A Under-user of inherit for is-a: overly complicated class YowooStaff Bugs/hacks? cali = YowooStaff(id: , name: CYLi, title: CFO)
- 23. Terminology
- 24. Instance Variables and Inheritance Staff: 1 instance variables YowooStaff: 2 instance variables
- 25. Instance Variables and Inheritance
- 26. instance variable binding: determined at compile time same name can NOT co-exist in a class, binding determined by compile-time type.
- 27. Instance Methods and Inheritance Staff: 1 instance method RD: 2 instance methods
- 28. what output?
- 29. instance method binding: dynamic, depending on run-time instance types
- 30. Reference Assignment saiLi is an instance of GoodStudent saiLi is an instance of Student, too one instance, many coherent types
- 31. Constructor and Inheritance initialize self 鍖rst, ancestor last the GoodStudent part of the memory initialized 鍖rst, the Student part
- 34. Private Variables and Inheritance
- 35. private variables are still inherited in memory, but not visible to the subclass because of encapsulation (security)
- 36. protected: accessible to Child(subclass)
- 37. public: everyone internal (default): same package classes protected: sub-classes private: class self Swift Access Permissions
- 38. Access Permission (Swift) Child: same or more close than Parent
- 39. References Apple: Access Control and protected http://commons.oreilly.com/wiki/images/a/a7/ Beyond_Java_I_2_tt13.png https://upload.wikimedia.org/wikipedia/commons/ thumb/4/47/C3_linearization_example.svg/600px- C3_linearization_example.svg.png https://developer.apple.com/library/content/ documentation/Swift/Conceptual/ Swift_Programming_Language/Art/ initializerDelegation02_2x.png