Structural Patterns

Structural patterns are concerned with how classes and objects are composed to form larger structures. They focus on simplifying the relationships between entities, making the system more flexible and easier to maintain.

The GoF categorizes 7 patterns into structural patterns, which can be broadly divided into two categories:

Class Structural Patterns (Using Inheritance)

• Adapter Pattern (Class Adapter): Converts one interface to another using multiple inheritance, allowing incompatible interfaces to work together.

Object Structural Patterns (Using Composition)

• Adapter Pattern (Object Adapter): Wraps an object to match a different interface through composition.
• Bridge Pattern: Decouples an abstraction from its implementation, allowing the two to vary independently.
• Composite Pattern: Composes objects into tree structures to represent part-whole hierarchies, treating individual and composite objects uniformly.
• Decorator Pattern: Attaches additional responsibilities to an object dynamically, providing a flexible alternative to subclassing.
• Facade Pattern: Provides a unified high-level interface to a set of interfaces in a subsystem, simplifying usage.
• Flyweight Pattern: Shares common objects to support large numbers of fine-grained objects efficiently.
• Proxy Pattern: Provides a surrogate or placeholder for another object to control access to it.