What is React JS?

• React is a powerful and flexible JavaScript library for creating user interfaces. Yes, you read that correctly; it's a javascript library, not a framework.
• React was created by Facebook in 2011 and has since grown to be one of the most popular JavaScript libraries. Facebook also maintains React.
• It breaks complex user interfaces into small, isolated pieces of code known as "components."
• React allows you to render multiple simple components to create a more complex one.

• React sorts the code into components, where each component maintains all the code needed to both display and update the UI.

• React is the most popular single page application builder. Single page applications are those application which loads only once and after tht every thing will be handled by JS.

Creating a development environment.

• Node JS must be installed on your PC before executing the below command in the terminal.

• Configure the React environment.

npx create-react-app my-app

• This is the best way to start building a new single-page application in React.

• This is not the only way to add React to your project. You can go through this link to find out more ways React Docs

Creating a basic Hello World app

• Creating a Hello World component.

function HelloWorld() {
  return (<h1>Hello World</h1>);
}

export default HelloWorld;

• Rendering the Hello World component.

import ReactDOM from 'react-dom/client';
import HelloWorld from './HelloWorld';

const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(<HelloWorld />);

• Output

• Each component contains an odd mix of HTML and JavaScript. React actually uses JSX, a language that allows HTML to be mixed with JavaScript.

• JSX allows you to use pre-defined HTML elements as well as create your own.

I hope that my article has helped you gain a basic understanding of React.

Thanks for reading