Software Design Patterns

Question 1

The scope of a design pattern has to do with what 2 sub-categories?

Answer 1

1. Class
2. Object

Question 2

What 2 criteria are used to classify design patterns?

Answer 2

1. Purpose
2. Scope

Question 3

What are 2 examples of the Factory Method?

Answer 3

1. C# GetEnumerator
2. JavaScript createElement

Question 4

What are Design Patterns?

Answer 4

A generalized way of solving common problems or types of problems in a given field

Question 5

What are the 3 purpose sub-categories for classifying design patterns?

Answer 5

1. Creational
2. Structural
3. Behavioural

Question 6

What classification is the Factory method?

Answer 6

Class Creational Pattern

Question 7

What does a behavioural class pattern do?

Answer 7

Uses inheritance to describe algorithms and flow control

Question 8

What does a behavioural object pattern do?

Answer 8

Describes how a group of objects cooperate to perform a task that no single object can carry out alone

Question 9

What does a creational class pattern do?

Answer 9

Defers some part of object creation to subclasses

Question 10

What does a creational object pattern do?

Answer 10

Defers object creation to another object

Question 11

What does a structural class pattern do?

Answer 11

Uses inheritance to compose a class

Question 12

What does a structural object pattern do?

Answer 12

Describes a way to assemble objects

Question 13

What else is the Factory Method know as?

Answer 13

Virtual Constructor

Question 14

What is an alternative to using a Singleton pattern?

Answer 14

A Global Variable

Question 15

What is the intent of a Singleton pattern?

Answer 15

Ensure a class has only one instance, and provide a global point of access to it

Question 16

What is the intent of the Factory Method?

Answer 16

Define an interface for creating an object and let subclasses decide which class to instantiate

Question 17

What type of pattern is a Singleton?

Answer 17

Object Creational Pattern

Question 18

Where does the idea of Software Design Patterns originate from?

Answer 18

Presentation by Kent Beck and Ward Cunningham

Question 19

Where does the term “Design Pattern” originate?

Answer 19

‘A Pattern Language’
a book about designing towns and buildings

Question 20

What type of pattern is an Abstract Factory?

Answer 20

Object Creational Pattern

Question 21

What is the intent of the Abstract Factory?

Answer 21

Provide an interface for creating families of related or dependent objects without specifying their concrete classes

Question 22

What else is an Abstract Factory known as?

Answer 22

Kit

Question 23

What type of pattern is Builder?

Answer 23

Object Creational Pattern

Question 24

What is the intent of the Builder pattern?

Answer 24

Separate the construction of a complex object from its representation to the same construction process can create different representations

Question 25

When should the Builder pattern be used?

Answer 25

1. Algorithm for creating a complex object should be independent of the parts that make up the object 2. Construction process must allow different representations for the object that's constructed

Question 26

What is the Director in the Builder class?

Answer 26

Accepts a builder and uses it to construct object

Question 27

How does the Builder create objects that's different from most creational patterns?

Answer 27

In parts

Question 28

What type of pattern is Composite?

Answer 28

Object Structural Pattern

Question 29

What is the intent of the Composite pattern?

Answer 29

Compose objects into tree structures to represent part-whole hierarchies.

Question 30

What else is an Adapter pattern known as?

Answer 30

Wrapper

Question 31

What type of pattern is Adapter?

Answer 31

Class and Object Structural Pattern

Question 32

What is the intent of the Adapter pattern?

Answer 32

Convert the interface of a class into another interface clients expect

Question 33

What is the difference between a Class Adapter and an Object Adapter?

Answer 33

Object Adapter calls a function on a member variable, whereas a Class Adapter calls a superclass.

Question 34

Which type of Adapter extends the class you're trying to wrap?

Answer 34

Class Adapter

Question 35

What is the purpose of a Two-Way Adapter?

Answer 35

Allow two different clients to view an object differently

Question 36

What are the 4 participants of the Factory pattern?

Answer 36

1. Product 2. ConcreteProduct 3. Creator 4. ConcreteCreator

Question 37

What is the product in a Factory pattern?

Answer 37

The interface type

Question 38

What are the 5 participants of the Abstract Factory?

Answer 38

1. AbstractFactory 2. ConcreteFactory 3. AbstractProduct 4. ConcreteProduct 5. Client

Question 39

What are the 4 participants of the Builder pattern?

Answer 39

1. Builder 2. ConcreteBuilder 3. Director 4. Product

Question 40

What is passed to the director in a Builder pattern?

Answer 40

ConcreteBuilder

Question 41

What is a Builder?

Answer 41

An interface

Question 42

What are the 4 participants of the Composite pattern?

Answer 42

1. Component 2. Leaf 3. Composite 4. Client

Question 43

What does the component do in a Composite pattern?

Answer 43

Declares the interface for objects in the composition.

Question 44

What are the 4 participants in an Adapter pattern?

Answer 44

1. Target 2. Client 3. Adaptee 4. Adapter