TechFastly is presenting this article to lead the way for you to understand why React became so popular in the market. If you are thinking of pursuing a career as a Front End Developer, you will want to know this beforehand. Let me tell you in advance, this is a beginner-friendly article that will get you all set to start React if you want to.

React Is A Library

React is a JavaScript library with which you can create user interfaces. The library here means that it is not a complete solution. The complete solution would have been if it was exactly a framework. React ignores other parts of the solution, for which you would need other libraries.

The real purpose is derived from the framework. Frameworks contain ready-made design decisions, and they are smart enough to form a complete picture of the application-level logic in your mind. Conversely, a framework can hurt experienced developers if they work on large codebases. The framework will force developers to code a certain way. This leads to a tussle between the framework and the developers.

Apart from this, the framework is large and full of features. You can't choose your needs freely and you have to pull the whole feature instead. Even though a lot of work is being done on this, it is not ideal. Some frameworks are converting to modular frameworks.

React is a small library and focuses on building user interfaces. React follows the Unix philosophy and creates the interface for users to come and interact with the machine. Whether it's the buttons on your TV or the dashboard of the Space Shuttle, everything is UI.

If the device you interact with understands JavaScript, we can use React on that. Now we've got browsers that understand JavaScript, so we build web UIs in React.

All you have to do is tell React what you want and it will create the UI on your behalf. Creating a UI with native web API and JavaScript is not that easy.

Whatever declarative descriptions we write in the React language, React will translate it into the actual UI in the browser. React is declarative and it shares its declarative power with HTML itself.

At its release, there was doubt about the performance and the reason for this was the virtual DOM. Virtual DOM can reconcile with actual DOM. But, the most important reason why it is popular today is the performance.

Most powerful thing is that it creates a link between developers and browsers, allowing developers to describe the UIs declaratively. You no longer need to act on DOM elements, you only need to act on the state of the UI. React automatically updates the UI whenever there is an action on the state.

Tree Reconciliation Algorithm

All the operations you perform in the DOM happen in a single thread, and this thread is responsible for everything that happens in the browser. It involves a lot of things like typing, scrolling, resizing etc. It simply means that as soon as you perform any expensive operation, you will get a janky experience.

You need to keep in mind that your application should always perform minimal operations and batch them wherever possible. React targets this concept.

When we render a tree of elements in React, React first creates a virtual representation of it and keeps it in memory. Now it performs DOM operations so that the tree can be viewed in the browser.

If you want to update this tree, React will create a new virtual representation of the updated tree. This means that there are two versions of the same tree in React. Now the thing to see is that React will not discard what React has rendered before.

That is version 1. Instead, it will compare both the virtual versions that are in memory.

While computing the difference between the two, it will look at which sub-tree is to be updated. React will update only those sub-trees in the browser. This is called the tree reconciliation algorithm and is very effective for working with the DOM tree of the browser.

Let me tell you that a ?virtual" browser is more friendly than a real browser. The DOM API is very difficult to work with. This is how React communicates with the DOM in your place.

The biggest advantage of React is for a developer who has very good JavaScript skills as it does not take much time to understand the React API. That is, if you call React "Just JavaScript" then it will not be wrong. Instead, if you approach a library that has a bigger API, it will take you a lot of time to master it. The best part is that the React API has functions and optionally classes. That is, the UI view that will be created will become a function of your data.

You can build native mobile applications with React Native. React will pay you off for iOS and Android mobile apps in the long run. Web, iOS and Android applications can share your logic.

Community

The React team at Facebook keeps adding new features and improvements so that the library is always better than ever. This maintains trust in the community. Production testing at Facebook is so strict that you won't find any serious bugs in any of the React releases. I think you are aware of the names of web applications that use React and they are Airbnb, Netflix, Twitter, and many more.

Wrapping Up!

React is competitive with Vue and Angular, yet it has become the preferred choice for developers. React is declarative, its community is awesome. With React Native, you can easily cover Android and iOS once you have a clear understanding of the basic architecture of React. React is SEO-friendly and fully embraces JavaScript. React will also save you a lot of time as it gives you component-based programming. Once your component is created, you can reuse it.