Structural

Question 1

Adaptor

Answer 1

Convert the interface of a class into another interface the client expects. Let classes work together that couldn’t otherwise because of incompatible interfaces.

Question 2

Facade

Answer 2

Provide a unified interface to a set of interfaces in a subsystem. Defines a higher-level interface that makes the subsystem easier to use.

Question 3

Decorator

Answer 3

Attach additional responsibilities to an object dynamically. Provide a flexible alternative for subclassing for extending functionality.

Question 4

Bridge

Answer 4

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

Question 5

Flyweight

Answer 5

Use sharing to support large numbers of fine-grained objects efficiently.

Question 6

Composite

Answer 6

Arrange objects into tree structures to represent part-whole hierarchies. Let clients treat individual objects and collections of objects uniformly.

Question 7

Proxy

Answer 7

Provide a surrogate or placeholder for another object to control access to it.