What Is ReactJS?

What Is ReactJS?

What is ReactJS?

ReactJS is a JavaScript library used to create reusable user interface components. According to the official React documentation, follows the definition -React is a library for creating modular user interfaces. It encourages the creation of reusable user interface components, which present data that changes over time. Many people use the React as the V in the MVC. React abstracts your DOM, offering a simpler programming model and better performance.

React can also render on the server using Node and can feed native applications using React Native. React implements unidirectional reactive data flow, which reduces cliché and is easier to reason than traditional data linking.

How does ReactJS work?

When creating client applications, a team of Facebook developers perceived that the DOM is slow (the document object model is an application programming interface for HTML and XML documents.) It establishes the logical structure of documents and the path of a document. document and in the case of a virtual domain, which is basically a representation of DOM tree in Javascript, so when you need to read or write in the DOM, it will use its virtual representation.,

The virtual DOM will try to find the most efficient way to update the browser DOM Unlike the DOM elements of the browser, the React elements are simple and inexpensive objects to be created React DOM takes care of updating the DOM to match the React elements The reason for this is that JavaScript is very fast and it is worth keeping a DOM tree to speed up its manipulation. Although the React has been designed to be used or in the browser, due to its design, it can also be used on the server with Node.js.

Become a ReactJS Certified Expert in 25Hours

  Why You Should Use ReactJS

  • js works very well for computers, strongly applying the user interface and workflow standards
  • The user interface code is legible and can be maintained
  • In addition, there is now a lot of demand for developers with the experience of ReactJS.

React Features

Currently, ReactJS is rapidly gaining popularity as the best JavaScript structure among web developers. It is playing an essential role in the front-end ecosystem.

The important features of ReactJS are the following:

  • JSX
  • Components
  • Unidirectional data connection
  • Virtual DOM
  • Simplicity
  • Performance


JSX stands for JavaScript XML. It is an extension of JavaScript syntax. It is a syntax similar to XML or HTML used by ReactJS. This syntax is processed in the JavaScript calls of the React frame. ES6 is extended so that HTML as text can coexist with the JavaScript response code. It is not necessary to use JSX, but it is recommended to use it in ReactJS.


ReactJS is all about components. The ReactJS application is composed of several components and each component has its own logic and controls. These components can be reusable, helping you to maintain the code when working on larger scale projects.

One-way Data Binding

ReactJS is designed to follow the unidirectional data flow or unidirectional data connection. The benefits of unidirectional data linking offer better control throughout the application. If the data flow is in another direction, it requires additional resources. It is because the components must be immutable and the data within them cannot be altered. Flow is a standard that helps keep your data unidirectional. This makes the application more flexible, which leads to increased efficiency.

Virtual DOM

A virtual DOM object is a representation of the original DOM object. It works as a unidirectional data connection. Whenever any modification occurs in the Web application, the entire user interface will be represented again in the representation of the virtual DOM. Next, check the difference between the previous DOM representation and the new DOM. Once done, the actual DOM will update only the things that really change. This makes the application faster and there is no memory waste.


ReactJS uses the JSX file, which makes the application simple and code, as well as understanding. We know that ReactJS is a component-based approach that makes reusable code according to your need. This simplifies use and learning.


ReactJS is known to be a great performer. This feature does much better than other frames today. The reason behind this is that it manages a virtual DOM. The DOM is a multiplatform and programming API that deals with HTML, XML or XHTML. The DOM exists entirely in memory. Because of this, when we create a component, we do not record directly into the DOM. Instead, we are writing virtual components that will become the DOM, leading to faster and smoother performance.

Get ReactJS Training with Real Time Project

Challenges or Limitation of ReactJS

  • ReactJS does not allow methods to be passed as additions so we can call a method that can change the state. We can not use the “State” value in the component function or function components written as a function
  • Integration with some of the MVC structures would require a person to be aware of which configuration changes to pass
  • Please remember that Each new CSS file created must be imported into ReactJS. The extension of the files can be issued only for JavaScript files, all other files must be explicitly mentioned
  • In the normal HTML attribute, names are case insensitive, we have to be careful when using case insensitive names.