Structural patterns are a category of design patterns that deal with organizing classes and objects to form larger structures. These patterns help define the relationships between the components of a system and make the system more flexible and easier to maintain.
Here are some commonly used structural patterns:
Adapter Pattern: The Adapter pattern enables collaboration between two incompatible interfaces by placing an adapter between them. The adapter translates calls from one interface to calls of the other interface, allowing objects to work together that otherwise couldn't directly communicate.
Composite Pattern: The Composite pattern allows treating individual objects and composite objects (made up of individual objects) uniformly. It enables the recursive composition of objects in a tree structure, making it easier to manage hierarchical relationships.
Facade Pattern: The Facade pattern provides a simplified interface to a more complex subsystem structure. It offers a single interface that accesses the underlying components and makes the system easier to use by hiding its complexity.
Decorator Pattern: The Decorator pattern allows dynamically adding additional functionality to an object without affecting other objects of the same type. It permits flexible extension of objects by "decorating" them with new features or behavior.
Bridge Pattern: The Bridge pattern decouples an abstraction from its implementation, allowing both to vary independently. It enables a flexible design by accommodating a variety of abstractions and implementations.
These structural patterns are powerful tools to improve the organization of classes and objects and enhance the flexibility and maintainability of software. When using structural patterns, it is essential to integrate them sensibly into the overall design and avoid overusing them, as this could increase complexity.