What is concatMap in RxJS?

Can you explain what concatMap does in RxJS?

Sure! concatMap is an operator in RxJS that maps each value to an Observable, then flattens all of those inner Observables in a sequential manner.

How is concatMap different from mergeMap?

The main difference is that concatMap waits for each inner Observable to complete before subscribing to the next one, while mergeMap subscribes to all inner Observables concurrently.

Can you give me an example of using concatMap?

Absolutely! For instance, if you have an array of user IDs and you want to fetch user details for each ID sequentially, you can use concatMap to ensure each request completes before the next one starts.

What are some use cases for concatMap?

Use cases include scenarios where order matters, like fetching data from APIs sequentially or processing tasks that depend on the completion of previous tasks.