All Tutorials

Your One-Stop Destination for Learning and Growth

Creating a Web Application using Express.js - Part 1: Installation and Introduction

In this blog series, we will explore how to create a web application from scratch using Express.js, a popular Node.js framework for building web applications. If you're new to Express.js or Node.js, don't worry! This tutorial is designed for beginners, and we'll go through the process step by step.

Prerequisites

Before we begin, make sure you have the following prerequisites:

  1. A basic understanding of JavaScript.
  2. Node.js and npm (Node Package Manager) installed on your system. You can download Node.js from official website and check the installation by running node -v and npm -v in your terminal or command prompt.
  3. A text editor or an integrated development environment (IDE) like Visual Studio Code, Atom, Sublime Text, etc.

Introduction to Express.js

Express.js is a fast, unopinionated, and minimalist Node.js web application framework that provides a robust set of features for building both simple and complex applications. Some of its most notable features include:

  • Routing: Express.js supports both HTTP and REST routing to handle different types of requests efficiently.
  • Middleware: Middleware functions are used to perform various tasks like authentication, logging, error handling, etc., in the request/response cycle.
  • Template engines: Express.js comes with built-in support for various template engines like EJS, Pug, Handlebars, and more.
  • Real-time web applications: Express.js supports real-time web technologies like Socket.io to build chat applications, live streaming, etc.

Installation

To get started with Express.js, let's create a new project. Open your terminal or command prompt and navigate to the directory where you want to create your new project:

mkdir express-app
cd express-app

Now initialize your Node.js application by running npm init -y. This command creates a package.json file with default settings. Next, install Express.js and its dependencies using the following command:

npm install express --save

To create your first Express.js application file, run touch app.js. Now open this file in your text editor or IDE and add the following code to create a simple HTTP server:

const express = require('express');
const app = express();
const port = 3000;

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

app.listen(port, () => {
    console.log(`Server is running at http://localhost:${port}`);
});

Save the file and start your server by running node app.js. You should see the message "Server is running at http://localhost:3000" in your terminal, indicating that your Express.js application is up and running. Open your web browser and visit "http://localhost:3000" to see the "Hello World!" message.

Congratulations! You've successfully created your first Express.js application. In the next part of this series, we will explore routing and middleware in Express.js. Stay tuned!

Published July, 2017