Welcome to the 21st century, C#, now that case blocks support a variety of pattern-matching formats.

. The "Chain of Responsibility" pattern as described in Design Patterns by Gamma et al. 1 can be a useful pattern, especially in projects that already have an established ownership composition ...

In the Observer design pattern, the state changes of an object are communicated to another object sans the need of the objects being tightly coupled with each other.