Object-Oriented Design
Which is the proper way to show inheritance in a UML class diagram? Choose one of the four options below:
c) Inheritance is shown in UML with an open arrowhead pointing to the superclass.
Choose the correct state diagram for a car which has a state called "HasGas:"
c) The state goes at the top, variables in the middle, and activities (including exit and entry activities) in the bottom.
There are three different relationships that objects can have. Which of these best describes the relationship between a Chair and its Legs?
composition
The first stage of the two-stage design process is _______ design.
conceptual
When during the design process are you likely to produce CRC cards the most?
conceptual design
You create an object that compares values from two different sources. It then updates the smaller value to be equal to the larger one. What kind of object is this?
control
Select the object pairing that has a composition relationship:
Book - Page
During model checking, what is the name for a violation of the desired properties of the model?
Counterexample
When two processes cannot run because they are waiting on the same resource, it's called...
Deadlock
Select the object pairing that has an association relationship:
Hiker - Trail
You are writing out a CRC card for a bank machine component. Under which section should you put "Track Cash Remaining."
Responsibility
How can you apply the principle of Separation of Concerns in object-oriented programming?
Separate objects or components according to their role in the software
Select the object pairing that has an aggregation relationship:
Stapler - Staple
Which one of these classes is in most need of being decomposed?
Store
What is the purpose of model checking?
To check the software for errors before release
For which of these situations would you use a sequence diagram?
To show the collaborative behaviour of objects in your program.
Choose the two answers that correctly complete the following sentence: : "We say that a class has low cohesion if..."
- ...its purpose is unclear. - ...it tries to encapsulate too many unrelated responsibilities.
Choose the three examples of inheritance used poorly:
- A method in the superclass is overwritten with different behaviour by a subclass. - A subclass inherits methods from the superclass and adds extra, new, unrelated functionality - Inheritance is used to share behaviour without specializing
Which two of these are likely to be a part of conceptual design?
- CRC Cards - Mockups
Two classes are tightly coupled. What are some ways you might be able to tell? Choose the two correct answers.
- In order to understand one class, you need to open up the other to look at the implementation - They are very highly reliant on each other
What are the best ways to promote Conceptual Integrity in your software? Choose the two correct answers.
- Regular code reviews - Planning the architecture of the system
What are the phases of Model Checking? Choose the 3 correct answers.
- Running Phase - Modeling Phase. - Analysis Phase
You are planning a Professor class as part of your software design. Which of these will you consider a collaborator ? Choose the two correct answers.
- Student - Course
What are some advantages of object-oriented programming in a language like Java? Choose the three correct answers.
- abstract data types - mimic the real-world structure of the problem - data management
During conceptual design, once the problem is mapped into components, what are the other two critical pieces of information that you must specify for these classes or components? Choose the two correct answers.
- collaborators - responsibilities
Identify two outcomes of the design process. Choose the two correct answers.
- conceptual design - technical design
Which of these terms are used to describe coupling? Choose the 3 correct answers.
- degree - ease - flexibility
You are writing the CRC card for a Bear component. Choose the three collaborators.
- den - tree - bear
Select the three categories of objects generally present in object-oriented software.
- entity - boundary - control
Which keywords allow your classes to achieve polymorphism in Java? Choose the two correct answers.
- extends - implements
You are writing the CRC card for a Bear component. Choose the two responsibilities.
- hunger - eat berries
Which of these are desirable characteristics of a software design? Choose the three correct answers.
- maintainability - flexible - reusability
Which of these conceptual design techniques will help you analyze the problem space to determine classes for your object-oriented software? Choose the two correct answers.
- mockups -CRC
Which of the following are examples of non-functional requirements? Choose the three correct answers.
- performance - availability - security
What are some keywords you might use for information hiding in Java? Select the three correct answers.
- private - protected - [none]
During conceptual design, you will talk about... (Choose the three correct answers):
- requirements - tradeoffs - mockups
What are elements of a state in a State diagram (see diagram)? Choose the three correct answers.
- state name - state variables - activities
In order to provide good encapsulation, fill-in-the-blanks on this UML class diagram: (Replace the underscores _ from top to bottom with minus signs ("-") or plus signs ("+"); your answer will be a string of six + or - signs with no spaces)
--++++
What is an abstract data type?
a type of data defined by the developer rather than the language.
You are writing a simple soccer video game. Select the best example of proper abstraction:
a)
Which of these UML class diagrams depicts an aggregation ("has-a") relationship between the two classes?
a) An open diamond indicates a weak "has a" or aggregation relationship.
Which of these elements represents a termination in a UML State diagram?
a) black filled circle inside another circle
Which of these sequence diagrams is correct?
b)
Which of these UML class diagrams shows an association relationship?
b) A simple association relationship is shown with a plain line, often with numbers indicating how many of each object can be associated.
Which UML class diagram is a good example of encapsulation? Choose one of the four options below:
b) This class has hidden the variables, then used getters and setters to allow access to them (and potentially add gatekeeping or value checking).
What is the term for reducing a class or object to its inputs and outputs in modelling?
black box thinking
An object which is responsible for showing data to the user could be considered which category of object?
boundary
You create an object that represents a dialog box. It creates buttons and text fields, etc, for the user to interact with, and it logs those interactions. What kind of object is this?
boundary
Which of these UML class diagrams depicts a composition, or a strong "has-a" relationship?
d) A filled diamond indicates a composition - or strong "has a" - relationship.
Sam decided that the DeliveryDriver class was getting too complex, so she split it up, moving its behaviour into several related classes, like DeliveryCar and DeliveryOrder. She just demonstrated which important object-oriented design principle?
decomposition
Information Hiding is closely related to one of the core design principles of object-oriented design. Which one?
encapsulation
Sam identified the important attributes and behaviours of a delivery driver and put them all into a DeliveryDriver class, like "takeOrder", "deliverOrder", and "DeliveryArea." She exposed some of these to other classes. She just demonstrated an important part of object-oriented design. Which of these concepts best describes what you did?
encapsulation
You create an object that represents a user, storing important information about them such as their preferences. What kind of object is this?
entity
Sam realized that her DeliveryDriver class had some behaviour and attributes that could be shared by other classes, like BusDriver and TaxiDriver, so she made a class called Driver that these classes inherited behaviour from. Which object-oriented design principle did she use?
generalization
Which design principle enables developers to follow the guideline D.R.Y. ("Don't Repeat Yourself"):
generalization
Which is the most desirable?
high cohesion, loose coupling
Some of the earliest computing languages supported:
main program and subroutines
Add the necessary keyword to complete this instance variable declaration in a class if you are using the encapsulation design principle to hide this variable from all other classes: ______ String message;
private
The second stage of the two-stage design process is ________ design.
technical
What is a requirement of this form called? "As a ____, I want to ____, so that ____".
user story
You are a programmer creating software for a bank machine system. Which section of a CRC card for the bank machine component will the "User" go into?
Collaborator
Which of these is an example of a quality tradeoff?
Adding security knowing it will reduce speed
When is Model Checking conducted?
After development
Sam was asked to create a DeliveryDriver class. Sam thought about the problem, and reduced it to its most essential aspects... things like takeOrder, DeliveryArea, etc. She ignored things that were not important in the context, like the driver's height or eye colour. She just applied an important object-oriented design principle. Which of these concepts best describes what she just did?
abstraction
Which of these violates Liskov's Substitution Principle?
an operation in the superclass is replaced by a different operation in the subclass
Which is the proper way to show an abstract method in a UML class diagram?
anOperation()
