JavaScript syntax extension permits HTML-like code within JavaScript files, commonly used in React for defining component structure. It simplifies DOM element manipulation by closely resembling HTML syntax. JSX facilitates the creation of reusable UI building blocks, defined as JavaScript functions or classes in React.

Prerequisites:

• Node or NPM
• React
• JSX

Steps to Create React Application And Installing Module:

Step 1: Create a React application using the following command:

npx create-react-app foldername

Step 2: After creating your project folder i.e. foldername, move to it using the following command:

cd foldername

Step 3: After setting up React environment on your system, we can start by creating an App.js file and create a directory by the name of components in which we will write our desired function.

Project Structure:

The updated dependencies in package.json file will look like.

"dependencies": {
    "react": "^18.2.0",
    "react-dom": "^18.2.0",
    "react-scripts": "5.0.1",
    "web-vitals": "^2.1.4",
}

Example 1: In this example, we will demonstrate how to add a class component in our application.

Javascript

Step to run the app:

npm start

Output:

Example 2: In this example, we will demonstrate how to add a class component in our application with a custom input by changing the contents of the header in the App.js file.

Javascript

Step to run the app:

npm start

Output: