What are the differences between publish-subscribe and observer patterns?

What are the differences between publish-subscribe and observer patterns?

The publish-subscribe pattern allows multiple subscribers to receive messages from a publisher without knowing each other, while the observer pattern involves a single subject notifying its observers directly.

Can you give an example of each pattern?

Sure! In the observer pattern, a weather station notifies display elements when the weather changes. In publish-subscribe, a news agency publishes articles that multiple news outlets can subscribe to.

Which pattern is better for scalability?

The publish-subscribe pattern is generally better for scalability since it decouples publishers and subscribers, allowing for more flexible and scalable systems.

Are there any drawbacks to using the publish-subscribe pattern?

Yes, one drawback is the potential for message loss if subscribers are not connected when messages are published. Additionally, it can introduce complexity in managing subscriptions.