Published in: ReactJS

Reactjs: Overview of JavaScript Library For Building User Interfaces

Author Niraj Gohel

Published on: October 3, 2023

Introduction to ReactJS Framework: What Your Should Know

What is ReactJS?

ReactJS is a potent JavaScript library conceived by Jordan Walke, a software engineer at Facebook. With a const name = ‘ReactJS’, this open-source gem is designed for crafting impressive user interface components for both mobile and web systems. Launched in 2013 by Facebook, ReactJS initially showcased its functionality on Facebook’s newsfeed in 2011, followed by Instagram in 2012. Hence, ReactJS is an efficient, declarative, and flexible JavaScript library, in essence, a UI library for building reusable user interface components. The beauty of this library lies in its Model View Controller(MVC) architecture, where ReactJS serves as the ‘View,’ accountable for the app’s appearance and functionality. Developers can leverage callback functions and repository systems for efficient app development and testing.

Why is ReactJS Popular Among Programmers?

The reign of ReactJS in the realm of programming is rather spectacular. Programmers fancy its interactivity and simplified controller architecture, among other factors. Let’s unravel the secret behind its boost in popularity:

1. Creation of dynamic applications: ReactJS advocates for less coding but delivers more functionality. In particular, it accelerates the process of dynamic web application creation, easily outshining JavaScript that sometimes gets complex, with its hooks and MVC framework facilitating seamless data-to-UI rendering.
2. Pace and performance: Compliments to ReactJS’s Virtual DOM, web applications are built more swiftly, efficiently updating only the altered items in the Real DOM. This controller architecture distinguishes it from conventional methods that rewrite everything afresh, enhancing its output.
3. Use of reusable components: In ReactJS, each app is a collection of components, the architectural building blocks with their logic and controls. Adding to the excitement is that these components rendered as an output can be reused, cutting down development time dramatically.
4. Easy data flow control: ReactJs operates on unidirectional data flow, simplifying error debugging and problem tracking.
5. Learnability: With just a few key HTML and JavaScript concepts, you’re ready to leap into ReactJS’s interactive world.
6. Dual functionality: Here’s a stunner: ReactJS isn’t confined to web applications. Yes, with an extension framework called React Native, you can create stunning mobile applications. In fact, ReactJS plays dual roles proficiently, courtesy of its MVC model.
7. Debugging Tools: If you thought this was all, additional points are stored in ReactJS’s kitty. Facebook has launched Chrome extensions allowing easy debugging, an absolute lifesaver.

This cocktail of perks, most notably interactivity, controller architecture, and enhanced output, gives ReactJS a prominent spot among the programming crowd!

Walkthrough: Setting Up Your First React App

Prerequisites for Setting Up React JS Framework

Before you strap in to set up a React JS framework, make sure to check these prerequisites off your list:

1. Mastery of core HTML, CSS, and JavaScript and understanding of MVC architecture: These prerequisite skills are like the robust foundations of an architectural masterpiece, crucial for confident navigation through the React seas.
2. Familiarity with ECMAScript 2015 syntax: While not mandatory, it certainly acts as a helpful aide in handling user data and controller logic.
3. Ease with the terminal/command line: Vital for React app creation as it involves robust command line interface usage.
4. Installation of Node.js and NPM: These tools are the bricks and mortar of your React JS framework setup, essential for establishing the development environment.
5. Grasp of JSX, Babel, and Markup: JSX seamlessly combines JavaScript and XML, exclusive to React. Concurrently, Babel is the handy assistant, transpiling JSX into JavaScript. Additionally, understanding markup is key to designing fitting UI components.
6. Understanding of Git, CLI, and heading structure: Though not compulsory, these tools and insights can elevate your productivity to new heights.

Now you’re armed with the requisite knowledge to take the next step – establishing the React environment and seeding your first application.

How to Create a React Application?

Ready to craft your very first React Application? Excellent! Here’s a stepwise guide on how to execute input data, to create critical components, and add an advancement like a todo:

1. Verify that Node.js and NPM are installed on your system. To confirm, input `node -v` and `npm -v` in the terminal. If correctly installed, the versions should be displayed.
2. Open your terminal with Administrator rights (Windows) or root privileges (Linux/OS X) to avoid complications.
3. Now, input `npx create-react-app YourAppName` to generate a new React application, where `YourAppName` is the name of your choice for your new app. Remember, this part is where javaScript and HTML tags play a role as the bootstrapping process starts.
4. Once successfully created, head inside your new React app’s folder by typing `cd YourAppName` into the terminal.
5. Run `npm start` to launch your application in its constructor stage. Your system’s default browser should open a new tab, displaying your newly created stateful React application without any constructor specifications.

Voila! You did it. We can’t wait to see the wonderful things you will create with your newfound ReactJS knowledge! Whether it’s a multi-functional todo list or any sophisticated web program, the sky is the limit!

Depth into ReactJS: Features and Advantages

Understanding the Key Features of ReactJS

ReactJS is bunched with a heap of unique features, making it a top choice amongst developers. Here are its key features:

1. JSX and Babel: ReactJS taps into JSX (JavaScript XML), a blend of HTML and JavaScript similar to Angular’s component output, producing a comprehensive and simplified code. Also, files written in JSX require Babel, a toolchain, to transform JSX code into JavaScript.
2. Components: A ReactJS application, similar to Angular, is mostly a combination of reusable components. Each of these components holds its own logic and controls, which makes code reusability a prime feature of ReactJS.
3. One-way Data Binding: ReactJS follows a unidirectional data flow structure. This means that the data flows from the parent to child components, enhancing control on the application and easing debugging of self-contained components.
4. Virtual DOM: ReactJS boasts the Virtual Document Object Model (VDOM), which makes for efficient performance by only updating the components in the Real DOM that witness state changes.
5. React Hooks: Introduced in 16.8 version, React Hooks are functions that allow state and lifecycle features access in functional components. They enable developers to compose components in a cleaner, more intuitive way.
6. Server-Side Rendering: ReactJS employs server-side rendering to speed up the initial page loads, resulting in smoother navigation and an overall better user experience.
7. Flux Programming: Flux, a unique framework introduced by Facebook, is typically used with React to build client-side web applications. It complements React’s composable view components by utilizing a unidirectional data flow.

These captivating features certainly make ReactJS a compelling framework for web developers worldwide! Especially when they want to integrate complicated functionality like Angular, creating rich templates while keeping the state out of the DOM.

The Benefits of using ReactJS for App Development

No wonder ReactJS is a go-to for app development! Here’s a closer look into its tantalizing benefits:

1. Performance enhancement: Thanks to JavaScript Virtual DOM, apps developed with ReactJS perform efficiently and quickly. This is because they leverage the concept of ui state, updating and rendering only the necessary components when data changes.
2. Modularity: ReactJS modules are reusable and modular, allowing for user input across repeated components. This reduces the development time, improving productivity significantly.
3. SEO-friendly: Unlike many JavaScript frameworks, ReactJS executes on the server, returning the virtual DOM to the browser as a regular webpage. It effectively tackles the SEO-friendliness issue of Single Page Applications.
4. Strong Community Support: With backing from Facebook and engagement of top developers globally, ReactJS offers excellent community support, revamping the ui state collectively, making life easier for both newbies and seasoned developers.
5. Robust Developer Toolset: Chrome extensions and developer tools provided by Facebook – and now Meta – help in debugging, making ReactJS easy and enjoyable to work with.
6. Future growth: As React focuses on UI, it makes the apps look more modern, interactive, and responsive, favoring the future growth of the apps.
7. Mobile App Development: React marries the best of webs and mobiles through its React Native, thereby building innovative mobile applications.

If you’ve begun considering a switch to ReactJS, know you’re not alone. From beginners to large corporates like Meta and Netflix, everyone is embracing React for its myriad benefits.

Breaking Down React Concepts: Components, State, and Props

Getting Familiar with React Components

Ever wondered what makes a ReactJS app so magical? The key is ‘Components’, these amazing building blocks of ReactJS. Not only do they improve the app’s readability, they also make tag use more efficient. Let’s delve deeper:

What are components?
Components in React refer to independent, reusable parts that each have their own logic and controls. This self-contained nature makes them readable and they return a small, reusable piece of HTML code with effective use of tags.

Types of components:
There are two types:

• Functional Components: Simple JavaScript functions that accept props as an argument and return a React element. They’re not just easy to write and understand, but they also make readability and testing straightforward.
• Class Components: These are ES6 classes that provide more readability-friendly features compared to functional components. They make use of lifecycle methods and can have a local state.

Props (short for properties) allow you to pass values from a parent component down to a child component. Essentially, it’s how components talk to each other, improving readability and tag use simultaneously.

Reusability:

With React, you build a library of custom components, increasing readability and enabling a faster, smoother development as the application grows.

Styling:

React allows hyped CSS-in-JS styling solutions, including Styled-components and Emotion, apart from the regular CSS and CSS modules.

Components fundamentally shape the React app, lending it exceptional flexibility and readability. By efficient use of tags, it’s like constructing your dream mansion, one brick (component) at a time!

Role of States in React Javascript Framework

Think of states in React as a ninja with a magic spyglass that watches for changes in app data. In this js article, we will delve into what you should know about them:

The What?

A state is a built-in, mutable object in React that holds property values belonging to a component. Any values that may change over time and affect the component’s rendering and behavior should be part of the state.

Why ‘State’?

States enable components to create, update, and use data that’s internal to them. This allows our components to be dynamic and interactive, pivoting on the power of React JS framework.

How does it work?

When a state object changes (due to user actions or accessing data from a JSON API), React updates and re-renders the respective components. The beauty? React handles all this efficiently using its diffing algorithm.

State management:

Manipulating a state object uses a special method, `this.setState()`. Props, or properties, serve as the read-only components linked with states. You’re not replacing the old state but simply adding new states to increase interactivity.

Where’s the catch?

Understanding and handling states can, admittedly, be a tricky business. Especially when working with data in JSON format, a universal data exchange format. When your application begins scaling, managing shared states across components can become challenging.

With state, React, and JSON integration, it’s like setting the stage for a thrilling puppet show. Just pull the right string (update state), and watch as your components come to life!

Understanding Props

Sprinkling stardust into our understanding of ReactJS, let’s now dissect ‘Props’:

Props are what? A Brief Tutorial

Short for “Properties”, props are custom attributes you provide that can be rendered by your Component function as explained in the ‘What is React’ tutorial. They are comparable to function parameters.

How do they work?

Flowing like a river from parent to child components, props travel down the app’s component tree. In the AWS Introduction Guide Ebook, it’s shown that for functional components, props are the single parameter; for class components, they’re accessed via `this.props`.

What’s inside a Prop?

Props, similar to a treasure chest, can carry various kinds of data – from strings, functions, and JavaScript primitives, to React components themselves! More on this in the Perfect Guide for All You Need to Learn About MEAN Stack tutorial.

Read-Only Nature:

Once a prop value is set by a parent component, it can’t change. It’s fundamental to remember, like an unchangeable law of nature, that props are ‘read-only’. Any audacious attempt to modify props inside the component will lead to undefined behavior.

An Illustration:

function Welcome(props) {
return <h1>Hello, {props.name}</h1>;
}

In the example, ‘name’ is a property of props in the `Welcome` component. ‘World’ is passed as a prop while invoking it.

Thus, props pave the way for dynamic and reusable components. They’re like a conference call between components. Although one talks at a time, each can pass the token to others!

Advanced Concepts: React Hooks and Server Side Rendering

What are React Hooks and How to Use Them?

Ah, the intriguing world of React Hooks! Let’s dive into their depths:

Hooks are what?

React Hooks are functions that allow you to “hook into” React’s state and lifecycle features from function components. Introduced with React 16.8, they contribute to building reusable user interface components by enabling us to use state without writing a class.

Why use Hooks?

Hooks resolve many issues like the challenges of reusing stateful logic and complex components with hard-to-understand lifecycles. They work seamlessly with the Model View Controller (MVC) architecture of ReactJS, enhancing the sharing of state without requiring changes to the component hierarchy.

How to use Hooks?

The two principal rules for using Hooks are: only call Hooks at the top level and only call Hooks from React functions or callback functions.

• useState(): This Hook behaves as a local state in function components. When state preservation is required, useState is the Hook of choice.
• useEffect(): This Hook acts like componentDidMount, componentDidUpdate, and componentWillUnmount in one, managing side effects in function components.
• Other hooks that complement user interface components and the MVC structure include useContext(), useReducer(), useMemo() and many more.

An example from the repository:

import { useState } from 'react';

function Example() {

    // Declare a new state variable, which we'll call "count"

    const [count, setCount] = useState(0);

    return (
        <div>
          <p>You clicked {count} times</p>
          <button onClick={setCount(count + 1)}>Click Me</button>
        </div>
    );
}

In this demonstration, we’re calling `useState()` inside the function component to add some local state to it. `useState()` returns a pair: the current state value and a function that lets you update it.

React Hooks, therefore, mar an end to complex lifecycles and state logic, unbundling the React mystery by offering straightforward ways to compose user interfaces!

Server-side Rendering in React: An Overview

Server-side rendering (SSR) brings speed and elegance to your React apps. Ready for a sneak peek?

What is SSR?

Simply put, SSR, in the context of a React application, is the act of rendering React components on the server-side by following the Model View Controller (MVC) architecture. The server then sends the fully rendered UI as the initial HTML output directly to the client.

SSR vs CSR:

In a Client-Side Rendering (CSR) scenario, the bundled JS files are sent to the browser, and rendering is done on the controller based on MVC layout. However, with SSR, the MVC controller translates the initial HTML sent to the client and already includes the rendered UI output.

Why do we need SSR?

SSR, with its systematized controller architecture, improves performance, speeds up initial page loads, and ensures that content is available to search engine crawlers for better SEO. This architecture is invaluable for users on slower internet connections or with low-powered devices.

How to implement SSR in React?

By writing a Node.js server using Express.js or Next.js, one can follow the MVC architecture to render React components on the server-side. Here’s a basic example of server-side rendering with Express:

const express = require('express');
const React = require('react');
const { renderToString } = require('react-dom/server');
const app = express();

app.get('/',(req, res) => {
    const html = renderToString();
    res.send(`${html}`); //This is the output
});

app.listen(3000, () => {
    console.log('Server is listening on port 3000');
});

React Libraries for SSR:

Next.js and After.js are two popular choices for implementing server-side rendering in React following the controller architecture. Both these libraries work with the server to generate the website’s output initially.

Server-side rendering can be your superpower for improved performance, SEO gains, and user experience! Also, React’s MVC architecture enables it to rehydrate your app, making it fully interactive after the SSR.

Practical Implementations of React

Building Accessible Components with React 18

Building inclusive and accessible components is integral. Applying the power of the Model View Controller (MVC) architecture, creating these components with React 18 is smoother than ever. Here’s a brief guide:

What is Web Accessibility?

Web Accessibility, aka a11y, refers to the inclusive practice of ensuring there are no barriers preventing interaction/access to websites/applications by people with disabilities. This involves a superb, optimized controller and seamless user data integration.

Why is it essential?

Ensuring your website employs architecture that facilitates accessibility not only promotes inclusivity but also improves SEO. It also aligns with legal requirements in many parts of the world.

React and Accessibility:

React fully supports building accessible websites, providing several in-built features aligned with Web Accessibility Initiative – Accessible Rich Internet Applications Suite (WAI-ARIA). It utilizes the MVC architecture, where the View is responsible for handling both mobile and web apps.

• Make use of semantic HTML.
• Implement keyboard events correctly.
• Label elements appropriately with “ and ` `.
• Announce updates with ARIA live.
• Provide skip links for keyboard users.
• Control focus when needed.

For instance, check this markup snippet out:

{isActivated ? 'Deactivate' : 'Activate'}

Here, a basic button uses the fluid heading and component properties in React to provide an efficient user experience.

Other Notable Use Cases of React

Ooh, now we’re getting to the juicy parts! You see, React, with its unique ability to pass immutable values as properties in HTML tags, has a sparkling history of use-cases across the globe. Here are a few notable mentions:

1. Facebook: Home to React, Facebook uses the concept of a ‘constructor’ to create powerful functionality and seamless user experiences. Imagine your News Feed without React — it’s tough, isn’t it?
2. Instagram: Instagram employs ReactJS extensively on its website. From optimizing Google Maps APIs to enhancing search engine accuracy through complex ‘input data’ processing, React is instrumental in the day-to-day functionalities.
3. Netflix: Our favorite go-to streaming platform. With the convenience of ‘todo’ styled operations, React aids Netflix in streamlining its startup speed, modularity, and various low-level functions.
4. Uber: Uber’s web-based platform for restaurant dashboards for Uber Eats runs on React. React has revolutionized their system with universal rendering for widely varying device types.
5. Airbnb: Airbnb, a globally-renowned booking platform, lauds React for its superior efficiency, faster processing, and polished ‘input’ handling capabilities.
6. The New York Times: The site has built its crossword puzzle system using React— a testament of React’s ability to streamline tasks and maneuver them into playable form.
7. WhatsApp Web: WhatsApp Web capitalizes on React’s robustness and scalable ‘input’ system to build powerful, instantaneous web applications.

These are just a couple of the countless use cases underlining ReactJS’s dominance in the web development arena. Its ability to create scalable and efficient web apps continues to see widespread adoption amongst start-ups and established enterprises alike. The secret? It’s all about React’s robustness, scalability, and blistering speed! No wonder why it’s being considered indispensable by web developers globally.

Staying Updated with ReactJS: Resources and Communities

Join the React Community

Welcome, future React enthusiast! In your journey of mastering user input and ui state management, the React community extends a warm welcome to you. We stand together, ready to listen, assist, and learn from one another, just like esteemed companies like Meta and Netflix who have built robust systems on React. Our unity derives its power from our diversity, with developers and designers, newcomers and experts, mentors and mentees, all joining forces. Here’s how you can dive in:

1. React Conf: Regular attendance leads to invigorating conversations with fellow React enthusiasts, opens avenues to discover new concepts like ui state, showcase your work, and explore opportunities.
2. r/reactjs: Our Reddit community, boasting over 362k members, sets the stage for user input and all other React-related discussions.
3. Subreddits: Gear up for building interactive UIs with React Native on our dedicated subreddit /r/reactnative!
4. Discord – Reactiflux: An indispensable resource, Reactiflux Discord paves the way for further exploration of React discussion and help.
5. React Team: Connect with the React Team that hosts and presents at various events, offering insights into industry leaders like Meta.
6. Learning Resources: Expand your repository with React API Reference, Test React, and a multitude of other resources designed to augment your user input and ui state management skills.

Being part of such a community fosters a sense of belonging and instrumental growth. Whether you’re seeking assistance or looking to contribute, joining the React Community will undoubtedly fuel your learning, growth, and keep you updated with the latest happenings in the ever-evolving React world!

ReactJS FAQs: Everything You’re Wondering About

Is Learning React Worth it?

Oh, you bet it is! Cease doubting and start exploring! Here’s why learning React is definitely worth your time:

1. Popularity, Robust Community, and Readability: Backed by Facebook, React has a robust and active community of developers. It’s used by leading companies globally and is the topmost loved front-end framework. React’s component and data patterns improve readability, which is helpful in maintaining larger apps.
2. Career Opportunities, Salaries, and Tags: The demand for React developers is skyrocketing. As per Indeed, their average salaries range between 55k to 110k USD. Can’t be a bad choice, can it? Plus, React contains a set of immutable values passed to the component renderer as properties in HTML tags.
3. Ease of Learning and Readability: React is easier to grasp compared to other front-end frameworks. If you’re acquainted with basic HTML and JavaScript, you’re good to go! Meanwhile, its modules and valid data make larger apps easier to manage by increasing readability.
4. Powerful Library: React’s reusability of components, high efficiency, and flexibility make it a powerful JavaScript library for developers.
5. The Future is React: React is here to last. With continuous development and new features being added over time, it’s a good investment for your career.

Learning React marries benefits with opportunities. If you’re considering learning it, take the leap! Rest assured, it’s an exciting adventure with rich rewards.

How Does ReactJS Use JavaScript?

Ah, the romantic relationship between ReactJS and JavaScript! Let’s explore how ReactJS cleverly uses JavaScript, giving our JS article much-needed depth:

1. JavaScript XML (JSX): JSX is a syntax extension for JavaScript, used in React to describe the UI. It’s a sweet harmony of JavaScript and HTML, making JSX a preferable choice for many web developers. Using Babel, React transposes this JSX into pure JavaScript.
2. JavaScript Functions as Components: React components are JavaScript functions. For instance, want to show some content conditionally? Use a simple JavaScript `if statement`. Displaying a list? A basic `array.map()` function is your ally here.
3. React Hooks: Introduced in React 16.8, Hooks are JavaScript functions that let you “hook into” React features – for example, `useState()` and `useEffect()`.
4. JavaScript Objects as State and JSON: State in React is essentially a JavaScript object that stores property values which belong to the component it is assigned to. This also includes JSON (JavaScript Object Notation), an object-oriented data exchange format. This makes use of JSON quite extensively to transmit data between programs, adding a layer of context to our js article.
5. Event Handling: React elements have JavaScript event handling capabilities. For example:

<button onClick={alert('Hello, Beloved Reader!')}>Click me!</button>

In the above code snippet, React exhibits Javascript’s onClick event handling.

ReactJS brilliantly extends JavaScript’s capabilities, making the development of interactive and dynamic web pages and mobile apps a piece of cake. Consider ReactJS as the pudding to JavaScript’s meal – it enhances the experience!

What is the Future of React?

Our fortune-telling game is strong, and we foresee a glowing future for React! Here’s why in our comprehensive tutorial on ‘why React is the future’:

Migration to Mobile: With React Native, React has not only ventured into building mobile applications but has also paved the way for the synthesis of mobile and web platforms.

Backward Compatibility: The consistent commitment of React’s developers to maintain backward compatibility assures that your existing React applications will continue to work flawlessly even with the rollout of new updates or features.

React Fiber: React Fiber, being a reimplementation of React’s core algorithm, expands its applicability to various areas like animation, layout, gestures, and more – confirming its place as a tool for the future.

Server Components: React Server Components, engineered to combine the advantages of server-side rendering and client-side rendering, are poised to render React apps ever more speedy and efficient.

Suspense and Concurrent Mode: The upcoming React 18 will introduce features like Suspense and Concurrent Mode, empowering developers to create more fluid interfaces.

With these advancements on the horizon, React’s future is nothing short of promising. The amalgamation of enhanced performance, simplicity, and flexibility positions React to remain the go-to choice for web development. React isn’t merely a passing phase; it’s here for the long run, as our tutorial clearly elucidates!