What are the design patterns in object-oriented programming?

Design patterns in OOP are divided into three main categories: creational, structural, and behavioral.

• Creational patterns — solve object creation problems. They help make a system independent of the way objects are created, composed, and represented. Examples:

  • Factory Method
  • Abstract Factory
  • Builder
  • Prototype
  • Singleton

• Structural patterns — define relationships between classes and objects. They help build larger structures from smaller ones. Examples:

  • Adapter
  • Bridge
  • Composite
  • Decorator
  • Facade
  • Flyweight
  • Proxy

• Behavioral patterns — define algorithms and relationships between objects. They help solve tasks of effective communication and responsibility distribution among objects. Examples:

  • Chain of Responsibility
  • Command
  • Iterator
  • Mediator
  • Memento
  • Observer
  • State
  • Strategy
  • Template Method
  • Visitor

The choice of a specific pattern depends on the problem to be solved and the context. Many patterns can be combined.