React Js | What Is It?


Introduction: What is React?

React.js was released by a software engineer working for Facebook – Jordane Walke, in 2011. React is a JavaScript library focused on building declarative user interfaces (UI) using a component-based concept. It is used to manage the view layer and can be used for web and mobile applications. The main goal of React is to be large, fast, declarative, flexible, and straightforward.

React Styled Components - The Compl...
React Styled Components - The Complete Guide

React is not a framework; it is specifically a library. The explanation for this is that React only deals with rendering UIs and reserves many things for the discretion of individual projects. The standard set of tools for building an application using ReactJS is often the stack.

Why use React?

Let’s look at what sets the React library apart from other frameworks and libraries and what makes it so powerful and popular for app development.

Virtual Document Object Model (VDOM)

The Document Object Model (DOM) is an API for valid HTML and well-formed XML documents.

A virtual DOM represents a real DOM constructed/manipulated by browsers. Advanced libraries, such as React, generate in memory a tree of elements equivalent to the real DOM, which forms the virtual DOM declaratively. The virtual DOM is one feature that makes the framework fast and reliable.


React uses a syntax extension for JavaScript called JSX. We use it to create


JSX uses Babel preprocessors to convert HTML-like text in JavaScript files into

JavaScript objects to parse.

React does not require JSX, but most developers find it makes for a more user-friendly experience in JavaScript code.

We use JSX to create React components; it’s an essential part of ReactJS.


React Native is an open-source JavaScript framework for building apps on different platforms, such as iOS, Android, and UPD. It is based on React and brings greatness to mobile app development.

React Native uses JavaScript to create an application’s user interface and uses native representations of the operating system. It allows implementation code in native languages of the operating system (Swift and Objective-C for iOS and Java and Kotlin for Android) for more sophisticated functions.

Main components

ReactJS is a component-based library where components make our code reusable and divide our UI into different elements. Members are divided into two types, class components and function components. All React components follow the design principle of separation of concerns, which means that we need to separate our application into different sections to address particular problems.

Functional components.

React components work the same way as JavaScript functions. A member takes random inputs, which we call props, and should always return a React element that defines what is intended to be displayed to the user.

The simple way to specify a React component is to define a JavaScript function and return a React element. The React component must always return a React element.

Otherwise, it will throw an error.

We have defined a ReactJS component called HelloWorld, which takes a prop that represents properties and returns a ReactJS element, a simple h1 element.

Class components.

The Class component must have the statement extend `React. Component`. This statement defines a `React. Component` subclass’ allows your part to access `React. Component` functions.

The component must also have a `render()` method, which returns HTML.

useState hook

The usestate is a Hook that allows you to have state variables in functional components. You pass the initial state to this function. It returns a variable with the value of the current state (not necessarily the initial state) and another process to update that value.


So the main question is why you should choose ReactJS as your front-end development stack when there are many others. Here are some reasons:

  • Without speed. React allows developers to use individual parts of their application on both the client-side and server-side, and any changes they make will not affect the application’s logic. This makes the development process extremely fast.
  • Component support. Using HTML tags and JS codes makes it easier to work with a vast dataset containing the DOM. React acts as a middleman representing the DOM and helps you decide which component needs changes to get accurate results.
  • Easy to use and learn. ReactJS is incredibly user-friendly and makes any interface interactive. It also allows you to build apps quickly and efficiently, saving time for customers and developers.
  • SEO friendly. A common problem that most web developers complain about is that traditional JavaScript frameworks often have SEO issues. ReactJS solves this problem by easily helping developers navigate different search engines because the ReactJS application can run on the server. The virtual DOM renders it and sends it back to the browser as a web page.
  • One-way data link. One-way data-binding means that anyone can track all changes to a data segment. It’s also one of the reasons why React is so easy.

Who uses React?

Here is the list of popular ReactJS websites:

  • Facebook
  • Atlassian
  • Uber eats
  • Netflix
  • Airbnb
  • Trello
  • Grammar
  • com
  • codecademy
  • dropbox

How to build your first app on React

  • Create your application on React.js from the terminal of your IDE
  • First, you need to install the framework package using `npx create-react-app`npx create-react-app my-app, where is your application’s `my-app` name.
  • The next step is to navigate through your new app.

`cd my-applications

  • And the last step is to start your application.

`npm start`

You will only have a front-end application with no database or backend, which takes a lot of work to get a full-fledged application.

What makes React JS so in demand right now?

The good thing about React JS is that its components are fast, reusable, and flexible. According to a recent survey, it has been revealed that React JS is one of the most well-known and demanded web frameworks. However, the most notable thing that makes React so unique is that it is pretty simple and helps developers build complex applications with ease.

What Skills Do React JS Developers Need?

To be a competent React JS developer, one needs to possess specific skills for getting react js jobs, which we have mentioned below.

  • Technical expertise
  • A thorough understanding of JavaScript.
  • Must be familiar with CSS, HTML, and some CSS frameworks.
  • In-depth knowledge of JSX, virtual DOM, and component lifecycle.● Must be able to master the Git Toolkit.

Besides those mentioned above, knowledge of WordPress, PHP, Magento, Opencart, MySQL, and Laravel is also imperative.

  • Soft skills
  • Innovation
  • Responsibility
  • Remarkable communication skills
  • Time management skills● Ability to solve problems



Amy Rey
the authorAmy Rey

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