Asked by: Odilo Cedrun
asked in category: General Last Updated: 27th May, 2020

Are observables asynchronous?

a Promise is always asynchronous, while an Observable can be either synchronous or asynchronous, a Promise can provide a single value, whereas an Observable is a stream of values (from 0 to multiple values), you can apply RxJS operators to an Observable to get a new tailored stream.

Click to see full answer.


Keeping this in view, are observables synchronous?

Observables can either be asynchronous or synchronous depending on the underlying implementation. An example of an asynchronous observable is one that wraps an http call. However when you are dealing with simple next-ing of values from a subject, the values will be received synchronously.

Furthermore, what is the difference between promises and observables? We could also say that the main difference between a promise and an observable is that a promise emits only a single value, whereas an observable emits multiple values.

Similarly, is RxJS asynchronous?

Conclusion. Although JavaScript is single-threaded, RxJS is follows the same principles as other libraries for reactive streams. We can create asynchronous streams, have some degree of concurrency and web workers even allow for parallelism.

Is subscribe asynchronous?

As you may know, subscriptions are used to handle async method call. Thus, the code inside the subscribe() method is executed only when the async method return its result (after a http call for instance). While waiting for the async response, the program continues and execute the following code.

30 Related Question Answers Found

What is asynchronous in angular?

What is synchronous and asynchronous in angular?

Is angular synchronous?


How do observables work?

What are observables in angular?

What are observables in JavaScript?


What is asynchronous code?

Can a callback function return a value?

Should I use promise or observable?


Why is a program reactive?

What is synchronous and asynchronous?

What is the difference between async await and promise?


Why do we need observables in angular?

What is RxJS used for?