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What is React? A Beginner’s Guide to JavaScript Library

React JS

September 18, 2023


In the world of web development, JavaScript libraries and frameworks play a crucial role in simplifying the process of building interactive and dynamic user interfaces. One such library that has gained immense popularity in recent years is React. Created by Facebook, React has become the go-to choice for many developers due to its efficiency, flexibility, and component-based approach.

Here, we will explore the fundamentals of React and its key features, providing you with a comprehensive introduction to this powerful JavaScript library.

To read more about integrating Django with React, refer to our blog How to Integrate Django With React in 2023

Understanding React

React is an open-source JavaScript library that allows developers to build user interfaces by creating reusable UI components. It focuses on the efficient rendering of components and updates only the necessary parts of the UI when the underlying data changes. React follows a declarative approach, where developers describe how the UI should look for any given state, and React takes care of updating the actual UI.

Component-Based Architecture

One of the core principles of React is its component-based architecture. In React, UIs are divided into reusable components, which encapsulate their own state and logic. Components can be composed and nested within each other, creating a hierarchy of UI elements. This approach promotes reusability, maintainability, and modular development, making it easier to manage complex UIs.

Virtual DOM

To efficiently update the user interface, React relies on a Virtual DOM (Document Object Model). The Virtual DOM is a lightweight reconstruction of the actual DOM that acts as a buffer between the developer’s code and the rendering engine of the browser. When a component’s state alters, React evaluates the Virtual DOM to the real DOM, detects the differences, and updates only the required sections. This reduces the number of costly browser manipulations required, resulting in increased performance.

JSX: JavaScript + XML

React introduces a syntax extension called JSX, It’s a syntax extension used in React that combines JavaScript and XML (eXtensible Markup Language) to describe the structure and appearance of components in a more intuitive and expressive manner. It allows developers to write HTML-like code directly within JavaScript, facilitating the creation of dynamic user interfaces.

JSX seamlessly integrates JavaScript expressions within curly braces {}. This allows you to embed dynamic values, variables, and JavaScript logic directly into the JSX code.

For example, you can include variables, perform calculations, or call functions within the JSX syntax.

const name = "John Doe";
const greeting = <h1>Hello, {name}!</h1>;

In the above code snippet, the variable name is embedded within the JSX code using curly braces. This enables the dynamic rendering of the value stored in the name within the resulting HTML output.

Unidirectional Data Flow

React uses one-way data binding, or unidirectional data flow. Data flows from parent to child components, ensuring that code is predictable and manageable. When a parent component’s state changes, React automatically propagates the changes to its child components, triggering re-rendering and reflecting the new state.

To read more about useState Hook in React, refer to our blog What is useState Hook in React & How to Manage State in Functional Components

React Ecosystem

React has a vibrant ecosystem with a wide range of tools and libraries that complement its functionality. Redux, React Router, and Axios are some popular examples. These tools enhance state management, routing, and data fetching capabilities, respectively. Additionally, React has a strong community that actively contributes to its development, providing support, tutorials, and reusable components.

React has revolutionized the way we build user interfaces in web development. Its component-based architecture, efficient rendering, and declarative approach make it an excellent choice for developing interactive and scalable applications.

By leveraging React’s ecosystem and following its best practices, developers can create robust and performant UIs. Whether you are a beginner or an experienced developer, learning React opens up a world of possibilities and empowers you to build modern web applications with ease. 

Horilla Editorial Team Author

Horilla Editorial Team is a group of experienced writers and editors who are passionate about HR software. We have a deep understanding of the HR landscape and are committed to providing our readers with the most up-to-date and informative content. We have written extensively on a variety of HR software topics, including applicant tracking systems, performance management software, and payroll software etc. We are always looking for new ways to share our knowledge with the HR community. If you have a question about HR software, please don't hesitate to contact us.