Build a simple Node.js Express web application

Intro

Node.js is a popular JavaScript runtime that allows you to run JavaScript on the server-side. Express is a web application framework for Node.js that makes it easy to create and run web applications.

The code I provided creates a new express web application and sets up a route that listens for incoming HTTP GET requests to the / path. When a request is received, the code sends a response with the text "Hello World!"

Prerequisites

To run the Node.js express web application, you will need to have the following prerequisites installed on your computer:

Node.js: This is a JavaScript runtime that allows you to run JavaScript on the server-side. I wrote how to install Node.js. Check it out here: How to install Nodejs.
npm: This is the package manager for Node.js, which allows you to easily install third-party packages and modules for use in your Node.js applications. npm is installed automatically when you install Node.js.

Initial project set

Create a new directory for your project and navigate to it in your terminal.
```
  mkdir node-express-web-app
  cd node-express-web-app
```
In the terminal, run the following command to create a new package.json file for your project:
```
  npm init -y
```

Install Express

Once you have these prerequisites installed and the initial set up, you can run the following command in your terminal to install the express package, which is required for the web application code to run:

npm install express

Create an express application file

Create a new file called app.js in your project directory and add the following code:

const express = require('express')
const app = express()

app.get('/', (req, res) => {
  res.send('Hello World!')
})

app.listen(3000, () => {
  console.log('My Express application listening on port 3000!')
})

To run this code, you would need to have the express package installed. You can do this by running npm install express in your terminal.

Run the Express application

In the terminal, run the following command to start the web server:

  node app.js

View the Express application

Open a web browser and go to http://localhost:3000/ to access the web application. You should see the "Hello World!" message displayed on the page.

Further modifications

You can modify the code in the app.js file to add more routes and functionality to your web application.

Conclusion

Node.js is a popular JavaScript runtime that allows you to run JavaScript on the server-side. Express is a web application framework for Node.js that makes it easy to create and run web applications.

To set up a Node.js express web application, you will need to have Node.js and npm installed on your computer. You can then create a new directory for your project, install the express package, and create a new app.js file with the web application code. Finally, you can start the web server by running the app.js file with the node command and access the web application in your web browser.

With a working Node.js express web application, you can add more routes and functionality to your web application by modifying the code in the app.js file. This can help you build powerful and dynamic web applications using Node.js and express.