If you've never heard of ReactJS, this is definitely the article for you. ReactJS is a JavaScript programming library or 'framework'. Let's look at one example to give you an idea of its use before we get into the details.


What is ReactJS?

When you examine a basic website's webpage, you will see a title area, side bar and main content page. Within these areas will be sub-layers. For instance, in the main content page, there can be a list with several list items and so on. For now, each of these components must be included independently to each page and will update only when a request is made to the server.

Using ReactJS, you can build a specific component with JavaScript and while holding the HTML language, it will also hold onto JavaScript logic (the 'JS' in ReactJS). These new components can now be incorporated and re-used within the webpage and site.

This is critically important now because the JS script can listen to user actions, display content dynamically and update the UI whenever it is needed without having to reach out to a server to fetch a new view.

Basically, ReactJS allows developers to create large web applications in-which the data changes without any reloading of the page. One use case that you may already be familiar with can be found using Facebook. Let's say your favorite celebrity posted a photograph and you clicked 'like' on the picture and decided to check out the comments. As you scroll through the comments, you notice the 'like' count has increase by 100 since your click.

This dynamically updating continuous change is the magic of ReactJS. The component you are looking at is constantly updating without reloading your page.

ReactJS is the V (View) in the MVC model of programming architecture. It is a JavaScript library used to help create user interfaces. Its main purpose is to be fast, scalable and simple.


Use Cases

Partial ReactJS Code Used
We mentioned Facebook earlier. They use ReactJS on parts of their webpage as the script is blended within the application code. Interestingly though, Facebooks mobile app uses an alternative version of React known as React Native, responsible for displaying iOS and Android native components rather than making use of DOM elements.

ReactJS is prevalent in a majority of Instagram's application. Numerous features including geo locations, Google Maps API's, search engine accuracy, all the way to tags used that pop out without hashtags. Instagram is completely based on the ReactJS library and is a premier example of its robust use.

Netflix uses a platform called Gibbon, which is used for low performance devices instead of using the DOM used in web browsers. To avoid latency on these devices, Netflix chose ReactJS library to increase the start-up speed, runtime performance, modularity and a variety of other advantages.

At about the time ReactJS was becoming popular with developers, Dropbox decided to see how using this library would improve their application. Dynamically refreshed file usage times, latency decreases due to the move from DOM to ReactJS increased the user experience significantly.

Startups to Fortune 500s
Thousands of companies have taken to ReactJS since it was released. React Native major clients include Airbnb, Walmart, Tesla for example as well as Tencent QQ with over 800 million active accounts. MOOG online education courses (Kahn Academy, Code Academy, Coursera etc.). The use cases are many.


Final Thoughts

Rendering is much faster and guarantees a stable code. React JS is definitely SEO friendly and comes with a great toolset that also works for a native mobile app development.

ReactJS has increased efficiencies, reduced risk, improved effectiveness and brought about numerous organizational benefits. Knowing all changes to upgrading take time and resources, it is absolutely worth the cost to create a better user experience whether in a browser or on mobile.