GoF Design Patterns

Question 1

Three categories of design patterns

Answer 1

creational, structural, and behavioral.

Question 2

What are design patterns?

Answer 2

elegant solutions to common problems

Question 3

4 elements of a design pattern

Answer 3

1. Pattern name
2. Problem
3. Solution
4. Consequences

Question 4

5 creational patterns

Answer 4

1. Abstract Factory
2. Builder
3. Factory Method
4. Prototype
5. Singlton

Question 5

Creational Patterns

Answer 5

Creational patterns provide various object creation mechanisms, which increase flexibility and reuse of existing code.

Question 6

Abstract Factory: Intent

Answer 6

Abstract Factory is a creational design pattern that lets you produce families of related objects without specifying their concrete classes.

Question 7

Abstract Factory: Use When

Answer 7

• a system should be independent of how its products are created, composed, and represented.
• a system should be configured with one of multiple families of products.
• a family of related product objects is designed to be used together, and you need to enforce this constraint.
• you want to provide a class library of products, and you want to reveal just their interfaces, not their implementations.