What is ExpressJS? Learn from Scratch

In this blog, we will go through everything you need to know about ExpressJS. From understanding the basic features of ExpressJS to learning its differences from NodeJS, this guide will give you a solid foundation. So, buckle up and let’s get started!

Table of Content

• What is ExpressJS?
• Why ExpressJS?
• ExpressJS vs NodeJS
• Features of ExpressJS
• Installation of Express JS
• Creating with Express JS
• ExpressJS Advantages
• Conclusion

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What is ExpressJS?

ExpressJS functions as a vital bridge connecting the front-end and back-end elements of a web application. Acting as an intermediary, it facilitates seamless real-time interaction between users and the application by efficiently processing and transmitting data. This framework offers a diverse range of beneficial features, such as middleware, routing, and templating, which greatly streamline the process of developing and maintaining web applications.

Technically, ExpressJS is an open-source web application framework, freely available, and built upon the Node.js platform. Its primary objective is to streamline the creation and management of server-side applications. With ExpressJS, you can effortlessly construct dynamic and interactive websites, establish RESTful APIs, and efficiently handle HTTP requests and responses.

ExpressJS caters to the needs of both novice and seasoned web developers. Its straightforward yet robust architecture makes it user-friendly and easily graspable, while its extensive feature set renders it suitable for developing intricate web applications.

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Why ExpressJS?

ExpressJS is widely acknowledged as a highly popular web application framework for Node.js, appreciated for a number of reasons:

• Simplicity: ExpressJS is renowned for its simplicity and minimalist design, offering a direct method for constructing web applications. This empowers developers with increased control over the architecture and components of their applications.
  
  
• Flexibility: ExpressJS offers a high degree of flexibility, allowing developers to choose and integrate various middleware, templating engines, and databases according to their project requirements. This flexibility enables developers to build applications tailored to their specific needs.
  
  
• Middleware: ExpressJS leverages a middleware-based architecture that empowers developers to enhance the functionality of their applications by integrating middleware components. These middleware functions can efficiently manage tasks like request and response processing, error handling, authentication, and an array of other functionalities. With the wide array of available middleware modules, extending the capabilities of an Express application becomes remarkably convenient and straightforward.
  
  
• Routing: ExpressJS offers developers a straightforward and user-friendly routing system that simplifies the definition of routes and the handling of HTTP requests. It boasts support for multiple HTTP methods, such as GET, POST, PUT, DELETE, and more, providing versatility in handling different types of requests. Additionally, ExpressJS allows developers to create custom routes and route parameters, enabling fine-grained control over the routing process. 
  
  
• Community and Ecosystem: ExpressJS boasts a vibrant and thriving community, resulting in an abundance of resources, tutorials, and modules at developers’ disposal. The extensive ecosystem surrounding ExpressJS encompasses a wide range of middleware, template engines, database integrations, and other valuable tools. This rich collection simplifies the process for developers to discover solutions and seamlessly integrate them into their projects.

ExpressJS vs NodeJS

ExpressJS and NodeJS are different from each other in many ways, some of them are:

• NodeJS is a JavaScript runtime that provides a platform for executing JavaScript code on the server side.
  ExpressJS, on the other hand, is a web framework built on top of NodeJS that provides a suite of tools for building and maintaining web applications.

• NodeJS focuses on providing a fast and efficient runtime for JavaScript, while ExpressJS focuses on simplifying the development of server-side applications.

• Both NodeJS and ExpressJS are popular choices for web developers, but ExpressJS is the preferred choice for building web applications and RESTful APIs.

NodeJS is used for a wider range of purposes, including server-side scripting and command-line tools.

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Features of ExpressJS

ExpressJS is a powerful web application framework that provides a range of features that make it easier to build and maintain web applications. Below are some of the key features of ExpressJS:

• Routing
  ExpressJS provides a simple and organized way to handle different HTTP requests and map them to specific actions. This allows you to define different paths for your website or API and specify what should happen when a user visits each one.
  
  
• Middleware
  ExpressJS uses middleware to process incoming requests before they reach their final destination. This allows you to perform tasks such as authentication, validation, and logging in a reusable and modular manner.
  
  
• Templating
  ExpressJS includes built-in support for several popular templating engines, such as EJS and Jade, which make it easier to create dynamic and interactive pages.
  
  
• Database Integration
  ExpressJS can be easily integrated with popular databases such as MongoDB and MySQL, making it simple to store and retrieve data in your web application.
  
  
• Easy to Learn
  ExpressJS has a simple and intuitive API that makes it easy to learn and use, even for beginner web developers.
  
  
• Scalable
  ExpressJS is designed to be scalable and efficient, making it suitable for building large and complex web applications.
  
  
• Large Community
  ExpressJS has a large and active community of developers who contribute to its development and provide support to one another. This makes it a reliable and well-supported framework for building web applications.

Go through Everything You Need to Know About NodeJS blog to know everthing about Node.JS.

Installation of Express JS

You can look into the following steps to install ExpressJS: Set up Node.js: Prior to installing ExpressJS, it is important to verify that Node.js is already installed on your system. If you want to know the steps to install and set up Node.js, do check out- https://nodejs.org/en/download

• Create a New Project Directory: Choose a directory on your system where you want your ExpressJS project to be stored before creating it. Next, open a command window or terminal and go to the desired directory.

• Initialize a New Node.js project: To commence the setup of a new Node.js project, navigate to the designated project directory and execute the provided command in the command prompt or terminal.

npm init

Executing this command will trigger a prompt that requests specific details regarding your project, such as the package name, version, and entry point. You have the option to either provide the requested information or simply press Enter to accept the default values.

• Install ExpressJS: Once the project initialization is complete, you can proceed to install ExpressJS as a dependency. Here is the following command which you can execute in your terminal: 

npm install express

Executing this command will trigger the download and installation of the most up-to-date version of ExpressJS, along with its associated dependencies, into your project.

• Create an Express Application: After the installation process is finished, you can proceed to create your Express application. Begin by creating a new file, such as “app.js,” and include the following code snippet:

const express = require('express');
const app = express();
// Define routes and middleware here
app.listen(3000, () => {
  console.log('Server started on port 3000');
});

This code sets up a basic Express application with a server listening on port 3000. You can define your routes and middleware in the appropriate sections of the code.

• Start the Server: Save the changes to the app.js file and run the following command in the terminal:

node app.js

Executing this command will initiate the server, and in the terminal, you should observe the message “Server started on port 3000.” Congratulations on successfully installing ExpressJS and configuring a fundamental Express application. You are now ready to begin the development of your web application using ExpressJS.

Creating with Express JS

Now let’s understand the working of express.js through an example.

Project Structure: Project Structure will be displayed in the image below:

Example: Write the following code in app.js:

var express = require('express');
var app = express();
app.get('/', function (req, res) {
res.send("Welcome to Intellipaat!");
});
app.listen(5000);

Step to run the application: Start the app by typing following command.

node app.js

Output:

ExpressJS Advantages

ExpressJS, widely adopted as a web application framework, presents numerous benefits for developers engaged in web application development. Here are some notable advantages of ExpressJS:

• Simplicity
  ExpressJS boasts a user-friendly and intuitive API, rendering it highly accessible and straightforward to learn and employ, even for web developers who are just starting out. This quality makes ExpressJS an excellent option for constructing web applications of varying sizes, particularly those in the small to medium range.
  
  
• Performance
  ExpressJS is specifically crafted to prioritize speed and efficiency, utilizing a lightweight architecture that empowers it to seamlessly manage significant traffic influxes with ease.
  
  
• Flexibility
  ExpressJS exhibits remarkable flexibility and versatility, accommodating the development of a diverse array of web applications, ranging from uncomplicated websites to intricate APIs. This characteristic renders it an adaptable choice for web developers, enabling them to meet the requirements of various project complexities.
  
  
• Integrations
  Integration of ExpressJS with other widely used technologies and frameworks, including databases, templating engines, and more, can be accomplished seamlessly. This effortless integration enables the construction of sophisticated and feature-rich web applications with ease.

Conclusion

To summarise, ExpressJS is a highly valuable and versatile web application framework that offers a range of features and benefits to developers building web applications.

Its simple and intuitive API, flexible architecture, and a large community of developers make it a great choice for building a wide range of web applications.

With its scalability, integrations with popular technologies, and high performance, ExpressJS provides a powerful and reliable platform for web development. Whether you’re just starting out or are an experienced web developer, ExpressJS is a smart choice for your next project.

Learning and growing as a web developer is an ongoing journey, and we’re here to provide you with the resources you need to succeed. Keep coming back to Intellipaat’s blog for more technical insights and tutorials.

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