INTRODUCTION TO PATTERNS

Question 1

Design patterns are

Answer 1

typical solutions to commonly occurring
problems in software design. They are like pre-made blueprints that you can customize to solve a recurring design problem in your code.

Question 2

The
pattern is not a specific piece of code, but a

Answer 2

general concept
for solving a particular problem. You can follow the pattern details and implement a solution that suits the realities of your
own program.

Question 3

While an algorithm always defines a clear set of actions that
can achieve some goal, a pattern is a

Answer 3

more high-level description of a solution. The code of the same pattern applied to two different programs may be different.

Question 4

The most basic and low-level patterns are often called

Answer 4

idioms.
They usually apply only to a single programming language.

Question 5

The most universal and high-level patterns are

Answer 5

architectural
patterns. Developers can implement these patterns in virtually any language. Unlike other patterns, they can be used to
design the architecture of an entire application.

Question 6

all patterns can be categorized by their intent, or
purpose.

Answer 6

1. Creational patterns
2. Structural patterns
3. Behavioral patterns

Question 7

The concept of patterns was first described by

Answer 7

Christopher
Alexander in A Pattern Language: Towns, Buildings, Construc-
tion1.Thebookdescribesa“language”fordesigningtheurban
environment. The units of this language are patterns. They
may describe how high windows should be, how many levels
a building should have, how large green areas in a neighbor-
hood are supposed to be, and so on.