What is the difference between the Observer Pattern and the Strategy Pattern?

What is the difference between the Observer Pattern and the Strategy Pattern?

The Observer Pattern is used for a one-to-many dependency between objects, where a change in one object triggers updates in others. The Strategy Pattern, on the other hand, defines a family of algorithms, encapsulates each one, and makes them interchangeable.

Can you give me an example of each pattern?

Sure! For the Observer Pattern, think of a weather station that updates multiple display screens. For the Strategy Pattern, consider a navigation app that can switch between different routing algorithms like fastest or shortest.

When should I use one pattern over the other?

Use the Observer Pattern when you need to notify multiple objects about changes in state. Use the Strategy Pattern when you want to switch between different algorithms or behaviors at runtime.

Are there any drawbacks to using these patterns?

Yes, the Observer Pattern can lead to memory leaks if observers are not properly removed. The Strategy Pattern can increase the number of classes in your codebase, making it harder to manage.