/ Design Patterns / Catalog Structural Design Patterns Structural design patterns are responsible for building simple and efficient class hierarchies and relations between different classes. Adapter Convert the interface of a class into another interface clients expect. Adapter lets classes work together that couldn't otherwise because of incompatible interfaces. Bridge Decouple an abstraction from its implementation so that the two can vary independently. Composite Compose objects into tree structures to represent whole-part hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. Decorator Attach additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extending functionality. Facade Provide a unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use. Flyweight Use sharing to support large numbers of fine-grained objects efficiently. Proxy Provide a surrogate or placeholder for another object to control access to it.