Structural Patterns

Question 1

What’s an composite and when to use?

Answer 1

Compose objects into tree structures to represent part-whole. Used when the programmer wants to create hierarchy of objects. To treat all objects in the composite structure uniformly (e.g: Draw()). One composite can contain a leaf or another composite.

Question 2

What is a decorator?

Answer 2

Also known as a wrapper. Decorator implements a given interface and may add extra functionality like adding borders before drawing child components.

Question 3

What is a bridge pattern?

Answer 3

It decouples an abstraction from its implementation so that the two can vary independently.