What is Reactive programming ?

Reactive programming is learning to program completely around synchronous data streams

So what the deference between Imperative programming and Reactive programming ?

Imperative programming focuses on the order in witch computer does things, Reactive programming only care about order in witch thing need to happen, they are written ignorant of the time and context in witch they are run.

If you are a Front-end developer, you probably already wrote a reactive code without even realizing it, YES, DOM events like key-press wait for stream of input data and respond accordingly .

Reactive programming is completely different from the sequential work flow. They react when something is done.

Let’s take an example from Rx(Reactive-Extensions) :
The combineLatest operator combine the latest expression is used to synchronize 2 Observable streams into single Observable stream.

The Combine Latest doesn’t using queue, as it name suggest it only remember the latest value of each stream.

We can see that when the y stream observed the b value, the result stream combine it with the latest value observed on x stream (3) and latter the same value will be combine into the result stream when the x stream will observed the 4 value.

The Combine Latest processing will come to end either when one of the stream

will complete or throw exception, in this case y Stream run complete(onComplete before RxJS5)

Did you feel lost ?

I felt the same thing the first time i read about reactive programming and RxJS, the hardest part of the learning journey is thinking in Reactive. It’s a lot about letting go of old imperative and stateful habits of typical programming, and forcing your brain to work in a different paradigm.

What about you? it worth learning nowadays ?