Exam(2024)

Question 1

What classification is the Proxy pattern?

Answer 1

Object Structural

Question 2

What else is the Proxy pattern known as?

Answer 2

Surrogate

Question 3

What is the intent of the Proxy pattern?

Answer 3

Provide a placeholder for another object to control access to it

Question 4

What is the motivation for using the Proxy pattern?

Answer 4

Defer full cost of its creation until we actually need to use it

Question 5

What are the 4 types of proxies? (Retarded Village People Smell)

Answer 5

1. Remote Proxy
2. Virtual Proxy
3. Protection Proxy
4. Smart Reference

Question 6

A smart pointer is an example of what kind of proxy?

Answer 6

Smart Reference

Question 7

What kind of proxy creates an expensive object on demand?

Answer 7

Virtual Proxy

Question 8

What are the 3 participants of the Proxy pattern?

Answer 8

1. Proxy
2. Subject
3. RealSubject

Question 9

How do the Proxy and the RealSubject interact?

Answer 9

Proxy forwards requests to RealSubject when appropriate

Question 10

What is it called when the Proxy pattern defers copying a large and complicated object until ensuring there has been a change to the object?

Answer 10

copy-on-write

Question 11

What classification is the Command pattern?

Answer 11

Object Behavioural

Question 12

What is the intent of the Command pattern?

Answer 12

Encapsulate a request as an object

Question 13

What else is the Command pattern known as?

Answer 13

Action, Transaction

Question 14

What is the motivation for the Command pattern?

Answer 14

Allow an object to make requests to unknown or variable receivers by making the request an object

Question 15

What are the 5 participants of the Commander pattern?

Answer 15

1. Command
2. ConcreteCommand
3. Client
4. Invoker
5. Receiver

Question 16

Which participant of the Commander pattern defines a binding between a Receiver object and an action?

Answer 16

ConcreteCommand

Question 17

ConcreteCommand implements which function that invokes corresponding operations on Receiver?

Answer 17

Execute

Question 18

What creates the ConcreteCommand and specifies its Receiver?

Answer 18

Client

Question 19

What stores the ConcreteCommand object?

Answer 19

Invoker

Question 20

What stores state for undoing a command when applicable?

Answer 20

ConcreteCommand

Question 21

Command decouples the object that invokes the operation from what?

Answer 21

The object that knows how to perform it

Question 22

What pattern can be used to combine many commands to create a MacroCommand class?

Answer 22

Composite

Question 23

What pattern can be used to implement Undos in the Command pattern?

Answer 23

Mementos

Question 24

What classification is the Chain of Responsibility pattern?

Answer 24

Object Behavioural

Question 25

What is the intent of Chain of Responsibility?

Answer 25

Decouple the sender of a request from the receiver by giving more than one object a chance to handle request

Question 26

What is it called when the object that makes a request has no explicit knowledge of who will handle it? (Chain of Responsibility)

Answer 26

Implicit Receiver

Question 27

What are the 3 participants of the Chain of Responsibility pattern?

Answer 27

1. Handler 2. ConcreteHandler 3. Client

Question 28

What 2 things are required in Chain of Responsibility handlers?

Answer 28

1. Interface to handle request 2. Accessor to Successor

Question 29

What classification is the Visitor pattern?

Answer 29

Object Behavioural

Question 30

What is the intent of the Visitor pattern?

Answer 30

To represent an operation to be performed on an existing class without changing that class

Question 31

Visitor should be used when an object structure contains many differing _______ and you want to perform operations that depend on their _______ _______.

Answer 31

Interfaces Concrete Classes

Question 32

Visitor should be used when classes defining object structure _______ _______ but you often _________ ________ __________.

Answer 32

Rarely Change Define New Operations

Question 33

Visitor should be used when many ___________ operations need to be performed on objects and you want to avoid making interfaces _________.

Answer 33

Unrelated Bulky

Question 34

What are the 5 participants of the Visitor pattern?

Answer 34

1. Visitor 2. ConcreteVisitor 3. Element 4. ConcreteElement 5. ObjectStructure

Question 35

Which participant in Visitor defines an Accept operation?

Answer 35

Element

Question 36

In the Visitor pattern, what does the Accept operation take as an argument?

Answer 36

Visitor

Question 37

Which Visitor participant can enumerate its elements?

Answer 37

ObjectStructure

Question 38

The Visitor pattern makes it difficult to add which participant?

Answer 38

ConcreteElement

Question 39

What OOP principle can be broken because of Visitor?

Answer 39

Encapsulation

Question 40

What is the intent of the MVC pattern?

Answer 40

Decouple visual and state classes

Question 41

What does MVC stand for?

Answer 41

Model View Controller

Question 42

What is the UI in MVC?

Answer 42

View

Question 43

What is the internal state in the MVC?

Answer 43

Model

Question 44

What is responsible for interaction in MVC?

Answer 44

Controller

Question 45

What is considered the source of truth in the MVC?

Answer 45

Model

Question 46

What has the responsibility of validating data in the MVC?

Answer 46

Controller

Question 47

What is the classification of the Interpreter pattern?

Answer 47

Class Behavioural

Question 48

What is the intent of the Interpreter pattern?

Answer 48

Describes how to define a grammar for simple languages, represent sentences in the language, and interpret these sentences

Question 49

What is a grammar in the Interpreter pattern?

Answer 49

Set of rules that construct a string

Question 50

What do you get when you combine all the expressions in a grammar?

Answer 50

Syntax Tree

Question 51

What 2 things make the Interpreter pattern work best?

Answer 51

1. Simple Grammar 2. Efficiency not critical

Question 52

What are the 5 participants of the Interpreter pattern?

Answer 52

1. AbstractExpression 2. TerminalExpression 3. NonterminalExpression 4. Context 5. Client

Question 53

In the Interpreter pattern, the client has a sentence built as an abstract syntax tree of what 2 types of expressions?

Answer 53

Terminal and Nonterminal

Question 54

Which type of expression defines the base case for the interpret recursion?

Answer 54

TerminalExpression

Question 55

The Interpret() function uses what to store and access the interpreter's state?

Answer 55

Context

Question 56

How does the NonterminalExpression define Interpret?

Answer 56

By the subexpression

Question 57

What pattern is a syntax tree?

Answer 57

Composite