Software Design Patterns

Question 1

what is a design pattern

Answer 1

a reusable design solution to a recurring design problem in a specific design context

Question 2

give the standard form of a design pattern (6)

Answer 2

name

structure

intent

motivation

implementation

applicability

Question 3

what do design patterns allow for

Answer 3

reuse of code and experience

shared vocabulary

Question 4

what are the three groups of design patterns

Answer 4

behavioural

structural

creational

Question 5

give two behavioural design patterns

Answer 5

state

strategy

Question 6

give two structural design patterns

Answer 6

adaptor

composite

Question 7

give two creational design patterns

Answer 7

factory method

singleton

Question 8

describe the strategy design pattern

Answer 8

create a set of objects that hold alternate algorithms to solve a problem

Question 9

describe the composite design pattern

Answer 9

common base class represents both part of object and its containing object

Question 10

describe the adapter design pattern

Answer 10

create a wrapper that converts incoming request into correct format

useful for legacy code

Question 11

describe the factory design pattern

Answer 11

create a class whose job is to create objects

Question 12

describe the singleton design pattern

Answer 12

create a class whose constructor is called differently and calls to create return instances of the same base class