What is difference between subscriber and observer?

Implements the Observer interface and extends the Subscription class. While the Observer is the public API for consuming the values of an Observable , all Observers get converted to a Subscriber, in order to provide Subscription-like capabilities such as unsubscribe .

What is pub/sub design pattern?

The Publish/Subscribe pattern, also known as pub/sub, is an architectural design pattern that provides a framework for exchanging messages between publishers and subscribers. This pattern involves the publisher and the subscriber relying on a message broker that relays messages from the publisher to the subscribers.

What is pub/sub mode?

Publish/subscribe messaging, or pub/sub messaging, is a form of asynchronous service-to-service communication used in serverless and microservices architectures. In a pub/sub model, any message published to a topic is immediately received by all of the subscribers to the topic.

What is difference between observer pattern and reactive programming?

As I understand it the difference is that Observer pattern concerns changes to an object where reactive programming concerns streams (as the Wiki article defines), observing a stream.

Why is pub/sub bad?

You might say that Pub-Sub is agnostic in terms of knowing about who is consuming messages. It may seem that way, but really when you think about it, the publisher does have knowledge. That knowledge resides in the topic….Things are Not as They Seem.

	Using Pub-Sub	Direct Access to Endpoint
Allows late binding	Yes	Yes

What is observable and observer?

Observer : Any object that wishes to be notified when the state of another object changes. Observable : Any object whose state may be of interest, and in whom another object may register an interest.

What is Observer pattern in JavaScript?

The Observer pattern offers a subscription model in which objects subscribe to an event and get notified when the event occurs. This pattern is the cornerstone of event driven programming, including JavaScript. The Observer pattern facilitates good object-oriented design and promotes loose coupling.

What is observer pattern in C#?

Observer is a behavioral design pattern that allows some objects to notify other objects about changes in their state. The Observer pattern provides a way to subscribe and unsubscribe to and from these events for any object that implements a subscriber interface.

What does observable mean in programming?

An Observable is simply a collection of data that waits to be invoked (subscribed) before it can emit any data. If you’ve worked with promises, then the way to access the data is to chain it with the then() operator or use the ES6 async/await .