Those who are in the know about all things tech have probably seen information about reactive programming, what it does, and how it works.

As we read through other articles on other sites, many of them aren’t exactly easy to understand. They can even seem confusing.

We are going to try to cut through the information and give everyone a more concise approach to what reactive programming is all about.

What is Reactive Programming?

Reactive programming is programming that utilizes asynchronous data streams. Typical events are asynchronous that we can watch or add extra effects.

When we create reactive programming, we’re creating data streams from events that happen as a result of variables, data structures, and just about anything.

Consider the Google Maps app, for instance. The app places a dot on your relative location and when you move, the dot moves with you. For example, if you had the app open while walking from your house to the grocery store, the dot marking your location would move with you in real time.

It does this by tracking your location, the acceleration of your device, and its position relative to North. Then, it combines those values and submits them to the API every few seconds. The API then returns a response to the UI Thread which then displays it to you, the user, as a little moving dot on a map. That’s reactive programming in a nutshell.

How is Reactive Programming Different from Functional Programming?

In reactive programming, we’ve got functional tools that make it possible to merge multiple streams. Together, this is functional programming.

Functional programming is useful when we want to filter streams to get specific events we want to know about. Various tools also make it possible for us to map data values between streams.

What is a Stream?

The short explanation of a stream is that it is a sequence of events that take place in order over time. Streams give us values, errors, and completed signals. With those, we can decide what happens next.

When streams are observed or listened to, the events that we want are what we respond to. This is also known as the Observer Design Pattern.

What Goes into a Reactive Framework?

Reactive frameworks, also known as reactive programming frameworks, are created with the express purpose of expressing application logic through streams that trigger what is known as side-effects.

There are various programming frameworks available for us to use in creating our streams and coding for the desired side-effects.

Frameworks can be powerful, the learning curve can be pretty tough, and the difficulty can sometimes be too much for some to be willing to take on these particular tools.

RxJS is one of those tools that can be overwhelming. It is a reactive extension or Rx, library-based in javascript. Learning RxJS is not easy and takes significant time and practice to learn and implement the framework.

RxAndroid was created to run similarly to RxJava, but it is just as difficult as RxJS. If we have a background or at least a preliminary understanding of reactive programming, it will be easier to understand what’s going on.

Top 5 Interesting Facts on How Reactive Programming Frameworks Work

Now that we’ve got all the basics out of the way, here are some interesting facts about reactive programming frameworks.

1. Data Streams are the Backbone to Our Applications

Every event is going to come from a data stream. That means any messages, calls, and even failures, are going to happen as a result of the stream.

To observe what happens in our stream, we need to know which observables we’re going to be utilizing within our code.

2. Cold and Hot Observables Make a Difference

Inside our code work, we will have created inherently asynchronous data streams. Within the code, our observables can be considered hot or cold.

Cold observables are passive and don’t do anything unless activated via subscribing with a reactive extension. Think about a file download – nothing happens until we click on the button to download.

Hot observables are active without an individual subscriber. Consider the way a stock ticker works – the information is available to anyone who wants to view it without having to click on anything.

Hot observables are best for sending the same data to multiple recipients or sharing new connections with multiple recipients.

3. Reactive Programming Does Not Create a Reactive Framework

Reactive frameworks are made of reactive systems. Reactive systems are designed to be responsive, resilient, and capable of stable message passing.

Being responsive means that our systems must handle a variety of requests in a reasonable time, even if there are times when there are more requests than normal.

Stable messaging is crucial because the different parts of a reactive system rely on the interaction via asynchronous messaging.

4. Practical Applications of Reactive Programming

Reactive programming makes it possible to express static or dynamic data streams through highly interactive mobile apps as well as web apps.

Using Rx, everything can become a stream. Like other programming, Rx begins as a stream of requests, followed by responses, and then finished by rendering the response or figuring out what to do with the said response.

As an example, Netflix utilizes reactive programming in its lineups. The platform receives upwards of 400 billion requests every single day. All events run alongside each other and produce quick and reliable responses to the clicks received from consumers across the globe.

5. Consumers Experience Greater Efficiency with Reactive Programming

Everything is interactive by use of reactive programming. Every application we use is reactive on the front end, but only since the adoption of reactive programming has that happened on the backend, too.

The asynchronous nature of reactive application development has resulted in programming that communicates with less chatter than its predecessors. Results to consumers include more efficiency with data that moves and responds in near real-time.

The Bottom Line

Reactive programming makes it possible for greater productivity via logic and data flow. Reactive systems allow for improvements to both resilience and scalability. Together, they both create the framework that embraces reactive programming that delivers a positive experience for consumers.