Getting Started with Express JS: A Beginner’s Guide to Backend Development (2023)

Express JS is a popular framework for building web applications in Node.js. It is known for its simplicity, minimalism, and flexibility, making it a favorite among developers for building backend systems. In this tutorial, we will provide an introduction to Express JS and guide you through the setup process, so you can start building your own web applications using Express JS.

What is Express JS?

Express JS is a lightweight and minimalistic web application framework for Node.js. It provides a set of features and tools to build web applications quickly and easily. With Express JS, you can create APIs, web servers, and single-page applications with ease. It is designed to be unopinionated, meaning it gives you the freedom to structure your application the way you want.

Setup Express JS

To get started with Express JS, you will need to have Node.js installed on your machine. If you don’t have Node.js installed, you can download it from the official website and follow the installation instructions.

Once Node.js is installed, you can create a new directory for your Express project and navigate to it in your terminal. To create a new Express project, you can use the following command:

$ npm init -y
$ npm install express

This will create a package.json file for your project and install the Express package. Next, you can create a new file called app.js and start writing your Express application.

Creating a Simple Express App

In your app.js file, you can create a simple Express application like this:

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

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

app.listen(3000, () => {
  console.log('Server is running on http://localhost:3000');
});

In this code, we import the express module, create an instance of the app, and define a route for the root path (‘/’). When a GET request is made to the root path, the server responds with ‘Hello, Express!’. Finally, we start the server on port 3000 and log a message to the console.

To run your Express application, you can use the following command in your terminal:

$ node app.js

Now, if you open your browser and go to http://localhost:3000, you should see the message ‘Hello, Express!’.

Conclusion

In this tutorial, we provided an introduction to Express JS and guided you through the setup process to create a simple Express application. Express JS is a powerful framework for building web applications and APIs in Node.js. It is easy to learn, versatile, and widely used in the industry. With the knowledge you have gained in this tutorial, you can start building your own web applications using Express JS.