CHAP018 (1)

Chapter 18 Object-Oriented Design and Modeling Using the UML

True/False Questions

1. An approach used to specify the software solution in terms of collaborating objects, their attributes and their methods is called object oriented design.

Answer: True Page: 646 LOD: Easy

2. An interface class is an object class that provides the means by which an actor can interface with the system.


3. A dependency relationship is illustrated with a dashed arrow line.


4. Navigability is illustrated with an arrowhead pointing only to the direction a message can be sent.


5. Visibility is the level of access an external object has to an attribute or method.


6. Method is the software logic that is executed in response to a message.


7. In a pure object-oriented environment every piece of code exists inside an object class.


8. An object-oriented system is structured into at least three different types of object classes.


9. Entity classes are identified during systems analysis and usually correspond to items in real life and contain information, known as attributes, that describes the different instances of the entity.


Whitten/Bentley, Systems Analysis & Design Methods, Seventh Edition 389


10. Interface classes are a means through which the attributes will interface with the instances of an entity.

Answer: False Page: 648 LOD: Medium Rationale: Interface classes provide a means for the user to interface with the system.

11. The responsibility of the interface class is twofold: (1) it translates the user's input into information that the system can understand and use to process the business event; (2) it takes data pertaining to a business event and translates the data for appropriate presentation to the user.

Answer: True Page: 648-649 LOD: Easy

12. Controller classes implement the business logic or business rules of the system.


13. System classes handle operating system-specific functionality.


14. By employing persistence classes, it allows the entity classes to be more implementation neutral and potentially more reusable.

Answer: True Page: 649 LOD: Medium

15. By employing persistence classes, it allows the entity classes to be more implementation specific and potentially more usable.

Answer: False Page: 649 LOD: Medium Rationale: By employing persistence classes, it allows the entity classes to be more implementation neutral and potentially more reusable.

16. Persistence classes read and write to a database.


17. Public attributes can be accessed and public methods can be invoked by any other method in any other class.


390 Whitten/Bentley, Systems Analysis & Design Methods, Seventh Edition


18. Private attributes can be accessed and private methods can be invoked only by any method in the class in which the attribute or method is defined.


19. A class responsibility is essentially the same thing as a class method.


20. A class responsibility is implemented by the creation of one or more methods that may have to collaborate with other classes and methods.


21. One technique for identifying behaviors is to search the use-case narrative for verb phrases.


22. A class responsibility collaboration (CRC) card is a popular tool for documenting the behaviors and collaborations for an object.

Answer: True Page: 657-658 LOD: Easy

23. Sequence diagrams show us in great detail how the objects interact with each other in time sequence.


24. In actor collaboration, the use case scenarios are acted out by the participants. The participants may assume the role of actors or object types that collaborate to process a hypothetical business event.

Answer: False Page: 664 LOD: Medium Rationale: This describes role playing.

25. Two overarching goals of object-oriented design are high coupling and low cohesion.

Answer: False Page: 666 LOD: Medium Rationale: Two overarching goals of object-oriented design are low coupling and high cohesion.



26. Cohesion is the degree to which one class is connected to or relies upon other classes.

Answer: False Page: 666 LOD: Medium Rationale: Coupling is the degree to which one class is connected to or relies upon other classes.

27. Ideally, object classes created for one information system should be able to be reused in other information systems.


28. Reusability is why operating system-specific code and database specific code are often designed into system and persistence classes.


29. A design pattern is a common solution to a given problem in a given context.


30. One advantage of using design patterns is that they provide designers with a short-hand notation for discussing design issues.


31. GOF behavioral patterns provide guidance on the way in which classes interact to distribute responsibility.


32. GOF creational patterns provide guidance for designing classes to instantiate new objects.


33. GOF structural patterns provide guidance on how classes can be designed to form larger structures.




34. GOF structural patterns provide guidance on the way in which classes interact to distribute responsibility.

Answer: False Page: 669 LOD: Medium Rationale: GOF behavioral patterns provide guidance on the way in which classes interact to distribute responsibility.

35. An object framework is a set of related, interacting objects that provide a well-defined set of services for accomplishing a task.


36. A component is a group of objects packaged together into one unit. An example of a component is a dynamic link library (DLL) or executable file.


37. A communication diagram is similar to a sequence diagram. But while a sequence diagram focuses on the structural organization of objects in a network format, a communication diagram focuses on timing of messages.

Answer: False LOD: Medium Rationale: A communication diagram is similar to a sequence diagram. But while a sequence diagram focuses on timing or sequence of messages, a communication diagram focuses on the structural organization of objects in a network format.

38. Communication diagrams depict the organizational units of programming code and how they interact.

Answer: False Page: 672 LOD: Easy Rationale: This describes component diagrams.

39. Deployment diagrams are also implementation type diagrams that describe the physical architecture of the hardware and software in the system. They depict software components, processors, and devices that make up the systems architecture.




Multiple Choice Questions

40. A class that would have to change if the system was ported to another operating system would be a(n): A) entity class B) interface class C) control class D) persistence class E) system class

Answer: E Page: 648-649 LOD: Medium

41. A class that contains the logic to run a use case would be a(n): A) entity class B) interface class C) control class D) persistence class E) system class

Answer: C Page: 648-649 LOD: Medium

42. Which of the following is NOT a UML level of visibility? A) private B) protected C) public D) persistent E) none of these

Answer: D Page: 650 LOD: Medium

43. Which of the following is NOT one of the activities of object-oriented design? A) Modeling class interactions, behaviors, and states that support the use-case

scenario. B) Refining the use-case model to reflect the implementation environment. C) Updating the class diagram to reflect the implementation environment. D) Updating the ERD to reflect public attributes and persistence classes. E) all of these are activities of object-oriented design




44. This is a popular tool for documenting the behaviors and collaborations for an object. A) cyclical redundancy collaboration (CRC) card B) class responsibility collaboration (CRC) card C) component responsibility collaboration (CRC) card D) classical responsibility collaboration (CRC) card E) none of these

Answer: B Page: 657-658 LOD: Medium

45. Which of the following is a tool that can be used for discovering class behaviors and responsibilities? A) CRC card B) sequence diagram C) class diagram D) a and b E) all of these

Answer: E Page: 657-659 LOD: Medium

46. What is an object state? A) a condition of the object at one time in its lifetime B) an occurrence that triggers a change in an object C) the act of simulating object behavior D) a method that displays the current state of the object E) none of these

Answer: A Page: 663 LOD: Medium

47. Which UML diagram models object state A) sequence diagram B) state machine diagram C) class diagram D) deployment diagram E) communication diagram

Answer: B Page: 663 LOD: Easy



48. What did the Gang of Four do? A) create the UML B) popularize the use of design patterns C) created CRC cards D) created a popular object framework E) battled Spider-man in issue #142

Answer: B Page: 669 LOD: Medium

49. Which of the following is NOT a GOF pattern category? A) evolutional B) structural C) creational D) behavioral E) none of these


50. If you needed to provide a stable interface to similar classes with different interfaces, you could use: A) the strategy pattern B) the adapter pattern C) a creational pattern D) the organizational pattern E) none of these


51. If you needed to design for varying and changing policy algorithms, you could use: A) the strategy pattern B) the adapter pattern C) a creational pattern D) the organizational pattern E) none of these




52. The process of using object-oriented techniques for designing a new system is referred to as: A) object oriented design B) class/object design C) reverse engineering D) database design E) none of these

Answer: A Page: 648 LOD: Easy

53. A dialogue box is an example of a(n): A) entity class B) interface class C) control class D) persistence class E) system class

Answer: B Page: 648-649 LOD: Medium

54. A class that handled reading and writing to a database would be an example of a(n): A) entity class B) interface class C) control class D) persistence class E) system class

Answer: D Page: 648-649 LOD: Medium

55. The student class in an enrollment system would be an example of a(n): A) entity class B) interface class C) control class D) persistence class E) system class

Answer: A Page: 648-649 LOD: Medium



56. What do you call a set of related, interacting objects that provide a well-defined set of services for accomplishing a task? A) class framework B) scenario C) object framework D) entity framework E) none of these

Answer: C Page: 671 LOD: Medium

57. This is a group of objects packaged together into one unit. An example is a dynamic link library (DLL) or executable file. A) scenario B) module C) subprogram D) component E) none of these


58. What is a design pattern? A) the obligation that an object has to provide a service when requested B) a common solution to a given problem in a given context. C) a set of related, interacting objects that provide a set of services. D) a group of objects packaged together. E) none of these


59. In which of the following are the use case scenarios acted out by the participants, where participants may assume the role of actors or object types that collaborate to process a hypothetical business event? A) scenarios B) plays C) role playing D) action play plans E) none of these




60. What diagram depicts how objects collaborate in message sequence to satisfy the functionality of a use case? A) state B) component C) sequence D) deployment E) communication


61. What diagram depicts the life cycle of a single object? A) state B) component C) sequence D) deployment E) communication


62. What diagram depicts the interaction of objects, focusing on their structural organization? A) state B) component C) sequence D) deployment E) communication

Answer: E Page: 672 LOD: Medium

63. What type of diagram is an implementation type diagram and used to graphically depict the physical architecture of the software system? A) state B) component C) sequence D) deployment E) communication




64. What type of diagram is also an implementation type diagram that describes the physical architecture of the hardware and software in the system and depicts software components, processors, and devices that make up the systems architecture? A) state B) component C) sequence D) deployment E) communication


65. Attributes and methods that are visible from any method in the class in which the attribute or method is defined or in subclasses of that class are said to be: A) private B) protected C) public D) persistent E) none of these


66. Attributes and methods that are visible from any method in any class are said to be: A) private B) protected C) public D) persistent E) none of these


67. Attributes and methods that are visible from any method in the class in which the attribute or method is defined are said to be: A) private B) protected C) public D) persistent E) none of these




68. Which of the following steps are NOT done in transforming the OOA class diagram into a design class diagram? A) add design object B) add attribute visibility C) add methods D) add dependency relationships E) all of these should be done


69. Which maxim best describes the rationale for using design patterns? A) A stitch in time saves nine B) Don't reinvent the wheel C) Haste makes waste D) A rolling stone gathers no moss E) The squeaky wheel gets the grease

Answer: B Page: 668 LOD: Easy

70. Which of the following is NOT an activity done in constructing a state machine diagram? A) Identify state transition paths B) Identify initial and final states C) Identify triggers D) Identify other states an object may have during its lifetime E) Identify other objects that trigger changes in the object's states


Fill in the Blank Questions

71. A(n) __________________________ is a group of objects packaged together into one unit. An example is a dynamic link library (DLL) or executable file.

Answer: component Page: 671 LOD: Hard

72. All objects are said to have ____________________________ - the value of its attributes at one point in time.

Answer: state Page: 663 LOD: Hard



73. A(n) _____________________________ triggers the change in state when something happens or when the value of one of the attributes changes.

Answer: state transition event Page: 663 LOD: Hard

74. ___________________________________ are a common solution to a given problem in a context.

Answer: design pattern Page: 668 LOD: Hard

75. A(n) ________________________________________ card is a popular tool for documenting the behaviors and collaborations for an object.

Answer: class responsibility collaboration (CRC) Page: 657 LOD: Hard

76. If an object calls its own method, it is called a(n) _______________.

Answer: self-call Page: 660 LOD: Hard

77. In ______________________________________, the use case scenarios are acted out by the participants. The participants may assume the role of actors or object types that collaborate to process a hypothetical business event.

Answer: role playing Page: 664 LOD: Hard

78. ________________________________ diagrams show us in great detail how the objects interact with each other over time.

Answer: Sequence Page: 659 LOD: Hard

79. _______________________________ is illustrated with an arrowhead pointing only to the direction a message can be sent.

Answer: Navigability Page: 650 LOD: Hard

80. __________________________________ diagrams show us how objects collaborate to satisfy the functionality of a use case, focusing on the structural organization of objects in a network format.

Answer: Communication Page: 672 LOD: Hard



81. _________________________________ diagrams are implementation type diagrams and are used to graphically depict the physical architecture of the software system.

Answer: Component Page: 672 LOD: Hard

82. _________________________________ diagrams are also implementation type diagrams that describe the physical architecture of the hardware and software in the system. They depict software components, processors, and devices that make up the systems architecture.

Answer: Deployment Page: 673 LOD: Hard

83. _________________________________ diagrams model the life cycle of a single object.

Answer: State machine Page: 663 LOD: Hard

84. Name four types of object classes that are introduced as a result of implementation decisions that were made during systems design: ___________________.

Answer: interface, control, persistence, system Page: 648-649 LOD: Hard

85. __________________________ classes are identified during systems analysis and usually correspond to items in real life and contain information, known as attributes, that describes the different instances of the entity.

Answer: Entity Page: 648 LOD: Hard

86. _________________________ classes are objects that are introduced to represent a means through which the user will interface or interact with the system

Answer: Interface Page: 648 LOD: Hard

87. The responsibility of a(n) __________________________ class is twofold: (1) it translates the user's input into information that the system can understand and use to process the business event; (2) it takes data pertaining to a business event and translates the data for appropriate presentation to the user.

Answer: interface Page: 648 LOD: Hard



88. _____________________________ classes are those that hold application or business rule logic.

Answer: Controller Page: 649 LOD: Hard

89. ________________________________ classes process messages from an interface class and respond to them by sending and receiving messages from the entity classes.

Answer: Controller Page: 649 LOD: Hard

90. _____________________________ classes read and write attributes to a database.

Answer: Persistence Page: 649 LOD: Hard

91. _________________ classes isolate the other objects from operating system-specific functionality.

Answer: System Page: 649 LOD: Hard

92. _____________________________ is the level of access an external object has to an attribute or method.

Answer: Visibility Page: 650 LOD: Hard

93. The process of using object-oriented techniques for designing a new system is referred to as _______________________________.

Answer: object-oriented design Page: 648 LOD: Hard

94. ________________________________ is the software logic that is executed in response to a message.

Answer: method Page: 651 LOD: Hard

95. The degree to which one class is connected to or relies upon other classes is called _______________.

Answer: coupling Page: 666 LOD: Hard

96. The degree to which all of the attributes and behaviors of a single class are related to each other is called _______________.

Answer: cohesion Page: 666-667 LOD: Hard



97. A(n) _____________________________________ is the obligation that an object has to provide a service when requested, thus collaborating with other objects to satisfy the request if required.

Answer: object responsibility Page: 651 LOD: Hard

98. During object-oriented design the class diagram developed during the analysis phase is refined into a ____________________________.

Answer: design class diagram Page: 665 LOD: Medium

99. A(n) __________________________________ is a set of related, interacting objects that provide a well-defined set of services for accomplishing a task.

Answer: object framework Page: 671 LOD: Hard

100. The authors of the 1995 book, Design Patterns, which proposed a set of 23 patterns for OO design are known collectively as the __________________________________.

Answer: Gang of Four Page: 669 LOD: Hard


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