This chapter discusses user-defined classes and abstract data types (ADTs) in Java. It covers defining classes with private, protected, public, and static members. Constructors and finalizers are examined. The toString method is explored. Abstract data types are introduced as data types that specify logical properties without implementation details. An example candy machine problem is presented to demonstrate defining classes for a non-GUI and GUI application to model a candy machine with items for sale, a cash register, dispenser, and other components.

1. Java Programming: From Problem Analysis to Program Design, 4e Chapter 8 User-Defined Classes and ADTs

7. Syntax The general syntax for defining a class is:

15. Unified Modeling Language Class Diagrams

17. Variable Declaration and Object Instantiation (continued)

18. Variable Declaration and Object Instantiation (continued)

22. Assignment Operator: A Precaution (continued)

23. Definitions of the Constructors and Methods of the class Clock

24. Definitions of the Constructors and Methods of the class Clock (continued)

25. Definitions of the Constructors and Methods of the class Clock (continued)

26. Definitions of the Constructors and Methods of the class Clock (continued)

27. Definitions of the Constructors and Methods of the class Clock (continued)

28. Definitions of the Constructors and Methods of the class Clock (continued)

29. Definitions of the Constructors and Methods of the class Clock (continued)

30. Definitions of the Constructors and Methods of the class Clock (continued)

31. Definitions of the Constructors and Methods of the class Clock (continued)

32. Definitions of the Constructors and Methods of the class Clock (continued)

33. Definitions of the Constructors and Methods of the class Clock (continued)

34. Definitions of the Constructors and Methods of the class Clock (continued)

35. Default Constructor or

36. Constructor with Parameters or

38. Method toString : class Clock

40. The Copy Constructor (continued)

43. Static Members of a Class (continued) void setX( int a) { x = a; } public String toString() { return ("x = " + x + ", y = " + y + ", count = " + count); } public static void incrementY() { y++; } } Illustrate illusObject = new Illustrate(); Illustrate.incrementY(); Illustrate.count++;

44. Static Members of a Class (continued) Illustrate illusObject1 = new Illustrate(3); Illustrate illusObject2 = new Illustrate(5);

45. Static Members of a Class (continued) Illustrate.incrementY(); Illustrate.count++;

55. Programming Example: Candy Machine (continued)

56. Programming Example: Candy Machine (continued)

57. Programming Example: Candy Machine (continued)

58. Programming Example: Candy Machine (continued)

59. Programming Example: Candy Machine (continued)

60. Programming Example: Candy Machine (continued)