Getting Started with ExpressJS

Introduction

Express is a popular Node web framework that also acts as the base library for several other Node web frameworks. It gives programmers the means to build handlers for requests made using various HTTP verbs at various URL paths, integrate with "view" rendering engines to produce responses by filling out templates, and set up standard web application parameters like the port to use for connection and the location of templates. To further handle practically any web development issue, Express enables developers to install middleware packages at each stage of the request handling pipeline. This high level of freedom benefits developers but also presents a potential barrier because choosing the best middleware packages and designing an application effectively can be challenging undertakings.

What is Express?

Express is a lightning-quick, straightforward web framework for Node.js. So what exactly does that mean? Let's dissect it. When we use the term "unopinionated," we mean that Express won't pressure you to act a specific way. It doesn't assume that you'll be creating your app or API using a specific design pattern or style, unlike some other frameworks. You have total control over how you respond to inquiries thanks to this. Additionally, because Express is so simple, it offers just the right number of functionality without getting in the way. You are allowed to construct anything you want in any way.

Express is frequently used in conjunction with well-known front-end frameworks like React, Angular, or Vue for the backbone of full-stack web applications. However, Express is effective on its own, offering an adaptable and reliable web server that you can quickly personalize to meet your requirements.

Still not sure what it’s all about? don’t worry, oftentimes the best way to learn is to dive right in and start building. And with this tutorial, you'll be up and running with Express in no time.

Why Use Express.js?

Express.js is frequently regarded as being superior to other frameworks of a similar nature as it is easy to use, pretty adaptable, and has extensive middleware choices. Express.js offers a thin layer between the developer's code and the server, unlike other high-level frameworks that enforce a specific design pattern or opinionated structure. This makes it more flexible and customizable by giving developers more freedom in how they want to handle requests and replies.

Another benefit of Express.js is its sizable and vibrant developer community, which has produced an abundance of middleware tools to solve practically any web development issue.

Express js is the best option for startup applications because it enables developers to quickly build a web server with little code. Its integrated routing system, which makes it simple to manage different endpoints, is another benefit.

In addition, Express supports a wide range of view engines, making it simple to create dynamic content and display HTML templates. This implies that programmers can create reliable web apps that can deliver tailored content based on user input or other variables quickly and simply.

It can construct RESTful services, which are a popular method of developing web services that can be accessed by many different clients. This is accomplished by utilizing HTTP techniques like GET, POST, PUT, and DELETE, which make it simple to modify server resources. Moreover, it makes it simple to serve static files like HTML, CSS, and JavaScript, which are crucial for creating contemporary web apps. Thus, responsive and user-friendly web apps can be quickly and simply built by developers.

Installing and Setting up Express

Time to start doing it! Let’s first see how we can get started with setting up expressJS on our system.

Step 1: Install Node.js and NPM: Ensure NPM and Node.js are set up on your machine. Node.js can be downloaded and installed from the main website here. Since NPM is included in Node.js you don’t have to download that

Step 2: Create a new directory: Create a new directory for your project and navigate into it using the command line First, you need to open your terminal or command prompt. This should be followed by the following command followed by the name of your directory (it can be anything! Go ahead and be creative)

Now let’s navigate into our newly created directory named my-express-app using the cd command. like this:

Great! Now we can start setting up our Express.js project.

Step 3: Initialise the project: To do so use the following command

You’ll see that a package.json file is created then, this file will contain information about your project.

Step 4: Install Express.js: Ah finally! use npm install express to install the Express.js framework and then add it as a dependency in your package.json file.

The project structure will look like the following.

How to Create a Web Application Using Express.js?

Now, let's look at the basic syntax of a web server.

Create a server file: Create a new server.js file in the project directory. This will serve as your application's starting place.

Import the required modules: On top of your server.js file to import the required modules add the following

Create a route: To create a route add the following to your code

The above code shall create a route that outputs "Hello World!" the moment the user (you) visits the homepage.

Start the server: To start the server add the following code to the end of your server.js file

This starts the server on port 3000 and the console would then shows you the printed message.

The code can be summarized as,

Test the application: Start the server using

You’d be greeted by “Hello World!” when you open your web browser and visit http://localhost:3000 .

There, you did it! You've successfully used Express.js to build an online application Now, you can expand the functionality and routes of your application the way you want