What is React.js?

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React.js is a Javascript library developed by Meta (formerly known as Facebook) that has revolutionized the way developers build user interfaces. It simplifies the process of creating dynamic and interactive web applications by using reusable components and a virtual DOM (Document Object Model) to efficiently update and render changes in the user interface. React.js is widely used and supported by a large community of developers, making it a popular choice for web development.

In this post, we will explore React.js’ applications, advantages, disadvantages, the vast ecosystem it offers, and how you can leverage it to build a career as a Web Developer.

What is React.js used for?

Web Application Development: React.js is extensively used for developing web applications of different sizes and complexities. It provides a flexible and scalable architecture that allows developers to efficiently build interactive and responsive UIs. Whether it’s a simple landing page or a complex enterprise application, React.js offers the necessary tools and components to create a seamless user experience.

Single-Page Applications (SPAs): React.js is well-suited for building SPAs where the entire application runs within a single web page. SPAs deliver a smoother user experience as they dynamically update content without requiring a page reload. React’s virtual DOM and efficient rendering make it an excellent choice for creating fast and responsive SPAs.

Mobile App Development (React Native): With the help of React Native, a framework built on top of React.js, developers can build native mobile applications for iOS and Android platforms using JavaScript. React Native allows code sharing between different platforms, reducing development time and effort. Many popular apps like Facebook, Instagram, Airbnb, and Skype have used React Native to create their mobile applications.

Is React.js for Beginners?

React.js is not for complete beginners to Web Development. It is a great choice for those who already have a basic understanding of HTML, CSS, and JavaScript. While React.js itself has a learning curve, it provides comprehensive documentation, a supportive community, and an abundance of learning resources. React.js follows a component-based approach, making it easier to understand and manage complex UIs. It is recommended to have a solid understanding of JavaScript fundamentals before diving into React.js.

React’s syntax is for the most part just Javascript. Here is a basic example of a React.js component:

import React from 'react';

function HelloWorld() {
  return (
      <h1>Hello, World!</h1>
      <p>Welcome to my React app.</p>

export default HelloWorld;

The code snippet above simply renders a heading and paragraph. Notice that a React component is basically a Javascript function. React components should be atomic and reusable. “Atomic” means components should have a single purpose.

How long does it take to learn React?

The time it takes to learn React.js depends on various factors such as prior programming experience, familiarity with JavaScript, and the amount of time dedicated to learning. It will likely take one to two months to learn hooks, common design patterns, and best practices. With a focused effort and consistent practice, a dedicated learner can grasp the fundamentals of React.js within a few weeks. However, becoming proficient and comfortable with advanced concepts may take several months or more. The key is to learn by doing, building small projects, and gradually tackling more complex applications. To learn React visit their official page (react.dev) and check out our other articles on React.

React.js Ecosystem and Libraries

React.js has a thriving ecosystem with a wide range of libraries and tools that enhance its capabilities. This gives it a definite competitive edge over other Javascript libraries and why it is unlikely React will go anywhere anytime soon. Some noteworthy libraries include:

  • React Router: A routing library for creating navigation in React applications. Our tutorial on React Router will help you get started.
  • Redux: A predictable state management library for managing complex application states. It provides a centralized and organized way to manage the state of an application, making it easier to understand and maintain. However, Redux is notorious for using a lot of boilerplate code and so new Javascript state management libraries like Zustand has gained more popularity.
  • React Query: A JavaScript library that simplifies data fetching, caching, and state management in React applications. It provides a declarative and hooks-based approach to handle server-state synchronization, making it easier to fetch, manage, and update remote data. Visit here to learn more.
  • Formik: A popular form management library that simplifies form validation and handling in React and React Native applications. Do you want to know how to use Formik in your React application?
  • MaterialUI: Material-UI is one of the most widely used React UI libraries. It is built upon Google’s Material Design guidelines and provides a comprehensive set of well-designed and customizable components. Material-UI offers a rich collection of UI elements, including buttonsformsnavigation, and more. Visit here to learn more.
  • Jest: A powerful testing framework for writing unit and integration tests in React applications. See here to learn more about how you can test your React applications.
  • Typescript: TypeScript is a statically typed superset of JavaScript that adds optional type annotations, enabling developers to catch errors early, enhance code maintainability, and improve developer productivity. Visit here to learn more.

Advantages of React.js

  1. Virtual DOM: React.js uses a virtual Document Object Model (DOM), which allows for efficient and optimized updates to the user interface. Instead of updating the entire DOM tree, React.js updates only the necessary components, resulting in better performance and faster rendering.
  2. Component-based architecture: React.js follows a component-based approach, where the UI is broken down into reusable components. This promotes code reusability, maintainability, and scalability, as components can be easily composed and combined to build complex user interfaces.
  3. One-way data flow: React.js follows a unidirectional data flow, meaning data flows in a single direction from parent components to child components. This makes it easier to understand and debug the application’s state, as data changes are predictable and traceable.
  4. Large and active community: As mentioned in the previous section, React.js has a thriving and supportive community of developers. This community contributes to the ecosystem by creating and maintaining numerous libraries, tools, and resources, making it easier for developers to find solutions, learn, and collaborate.
  5. React Native: React.js has a companion framework called React Native, which allows developers to build mobile applications for iOS and Android platforms using the same React.js concepts. This means that developers can leverage their existing React.js knowledge to develop cross-platform mobile apps, saving time and effort.

Disadvantages of React.js

React is not optimized for Search Engine Optimisation (SEO) because it relies on client-side rendering. Also, React’s tooling can be complex and overwhelming for a beginner. React is a library for building user interfaces and it does not provide a complete solution for building a full-fledged application. Developers need to choose and configure additional tools and libraries for tasks such as routing, form handling, and state management. The wide range of available options can sometimes make it challenging to decide on the best tooling setup.

React’s SEO Challenges

React applications can face SEO challenges due to client-side rendering, delayed content loading because of asynchronous data fetching or lazing loading, lack of meta tags, and lack of dynamic URLs. These factors can potentially impact the visibility and indexing of React applications in search engine results, requiring additional effort to optimize them for SEO. React applications are typically rendered on the client side using JavaScript. This means that when search engine crawlers visit a React application, they may initially encounter a blank or partially rendered page since JavaScript needs to be executed to render the content. Search engines may not wait for JavaScript execution and may not effectively crawl and index the page’s content, leading to poor visibility in search results. To fix this problem, Server-Side Rendering (SSR) comes to the rescue, and the best React framework to achieve this is Next.js. Implementing SSR allows the server to render the initial HTML markup of the React application before sending it to the client. This ensures that search engine crawlers encounter fully rendered content and can effectively index it.

Next.js is a popular full-stack framework built on top of React.js that adds server-side rendering (SSR) and other features to enhance React.js applications. It provides a set of tools and conventions to simplify the development process and improve performance. One of the key advantages of Next.js is its ability to handle both server-side rendering (SSR) and client-side rendering (CSR) seamlessly, allowing developers to achieve the benefits of both approaches.

Next.js will only continue to grow in popularity. Visit our comprehensive guide on Next.js to get started learning.

With Next.js, developers can easily create dynamic, fast, and scalable web applications. It offers built-in support for server-side rendering, which enables faster initial page loads and improved search engine optimization (SEO). Next.js also provides automatic code splitting, allowing for the efficient loading of JavaScript and other assets. Additionally, it offers features like pre-rendering, static site generation, and incremental static regeneration, which help optimize performance and deliver a smooth user experience.

Unlike React.js, Next.js comes with a robust routing system that allows for easy navigation between pages. It also supports API routes, enabling the creation of serverless API endpoints within the same project. The framework integrates seamlessly with popular tools and libraries in the React ecosystem, making it highly flexible and extensible. Moreover, Next.js has excellent developer experience with features like hot module replacement, fast refresh, and comprehensive error reporting, which aid in efficient development and debugging. Its broad community support and active development make Next.js a reliable choice for building modern web applications.

Making Money as a React.js Developer

So, if you have been this far, it likely means you are seriously considering learning React. Here are several ways you can leverage this skill to make money:

  1. Full-time employment: Many companies and organizations are in constant need of React.js developers to build and maintain their web applications. You can explore full-time job opportunities with startups, tech companies, or established enterprises. Stay up to date with job postings on career platforms, professional networks, and company websites. A full-time position provides stability, benefits, and a consistent income.
  2. Freelancing: One of the most common ways to earn money as a React.js developer is through freelancing. You can offer your services on freelance platforms like Upwork or Fiverr or reach out to clients directly. Build a portfolio showcasing your React.js projects and highlight your expertise. Freelancing allows you to work on various projects, collaborate with different clients, and charge hourly rates or project-based fees.
  3. Creating and selling React.js components or templates: If you have expertise in building reusable React.js components or complete templates, you can create and sell them on marketplaces like CodeCanyon, ThemeForest, or your own website. Developers and businesses often seek high-quality, customizable components and templates to speed up their development process. By creating and selling these assets, you can generate passive income.
  4. Teaching and consulting: With your expertise in React.js, you can offer consulting services to businesses looking to adopt or optimize React.js in their projects. Additionally, you can create educational content like tutorials, courses, or eBooks to teach others React.js development and earn income through subscriptions, sales, or advertisements.


Can I use React.js for mobile app development?

No, but you can use React Native which is a mobile framework that is built on top of React.js and allows developers to build mobile applications for iOS and Android platforms using JavaScript and React.js syntax.

What are some good resources for learning more about React.js?

The official React.js documentation (https://react.dev) is a great place to start and includes tutorials, guides, and API references. Other helpful resources include online courses and tutorials, books, and developer communities such as Reddit’s r/reactjs.

Do I need to know JavaScript before learning React.js?

Yes, a solid understanding of JavaScript is necessary to work with React.js. Familiarity with ES6 syntax and concepts such as arrow functions, promises, and destructuring can also be beneficial. To learn more visit here.

What other libraries or frameworks work well with React.js?

React.js can be used with a variety of other libraries and frameworks such as Redux for state management, React Router for handling routing and navigation, and Axios for making HTTP requests. You can use Next.js for Server-Side Rendering (SSR).

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Rajae Robinson

Rajae Robinson is a young Software Developer with over 3 years of work experience building websites and mobile apps. He has extensive experience with React.js and Next.js.

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