ExpressJS Tutorial

As ExpressJS simply puts it,

“It is a fast, unopinionated, and minimalist web framework for Node.js."

Express is a simple web framework for Node.js technology. As its name indicates itself, express meaning fast. It allows developers to build APIs, web, mobile and cross-platform applications easily and quickly. It is an open-source framework that simplifies the development process of server-side applications by using JavaScript as its programming language.

At its core, ExpressJS is designed on top of Node.js, which means, it takes benefits of its flexibility and performance. As a result, it makes it easier for developers to develop scalable and responsive web applications. With the help of middleware, ExpressJS allows developers to route, handle, and process HTTP requests with ease.

It also facilitates unopinionated nature, which means there is no structural way to write a code. You can utilize it in varied manners. You can also develop single-page, multi-page, and hybrid web applications with ExpressJS.

In addition, it has a simple and intuitive API (application programming interface) that assists developers with the building blocks to create web applications. It also provides feature-rich functions, such as routing, template engines, and middleware support. Overall, it has proved to be an excellent choice for developers to develop fast, scalable, and reliable web applications with minimal coding.

TJ Holowaychuk was the creator and founder of the ExpressJS Framework. He was a prolific developer in the Node.js community. Being highly dissatisfied with the complexity and limitations of other Node.js frameworks, he developed ExpressJS.

At the very start of ExpressJS, it was a basic framework that was designed to provide support for basic routing and middleware functionalities. Meanwhile, the Node.js community found its minimalist and flexible approach an attractive alternative. Over the years, ExpressJS has continued to grow significantly.

As per the information available on ExpressJS’s GitHub repository, it was first released on May 22, 2010. Later, In June 2014, the project was taken by StrongLoop and saw a noteworthy update with the release of version 4. It came with a powerful routing system, improved error handling, and other feature-rich functions.

Further, in September 2015, IBM acquired Strong Loop. Finally, in January 2016, it was declared that ExpressJS would be managed under the Node.js foundation incubator by IBM. Meanwhile, the teams behind ExpressJS introduced version 5. It updated the entire framework to support the latest version and incorporated additional features.

Today, ExpressJS is one of the universally used Node.js frameworks within development communities. It has come a long way since its launch, and now its persistent success stands as undeniable evidence of its effectiveness and buzz in the Node.js community.

Today, the most important asset of every business is their time. And ExpressJS can build quality web applications effectively and efficiently. With the help of its minimalist approach and flexible nature, it's not just easy to use but helps to build applications faster than ever before.

Want to explore Node Express in your next project?

We have covered enough grounds with ExpressJS, so let’s discover why you should choose it:

1. Easy to Learn

Having a minimalist design, ExprssJS is easy to learn and access. It is designed on the top of Node.js which means those already familiar with Node.js can simply get started with ExpressJS. It is considered as the perfect framework for newbies who are just starting their programming journey.

2. Quick Development

ExpressJS is a full-stack JavaScript framework that can cut down the development time by half and efficiently build a web application. By utilizing its modular design, middleware support, and other feature-rich functions, ExpressJS is a perfect choice for fast development.

3. Better Coding Facility

Are you frustrated with clunky codes and silly errors? ExpressJS has gotten you covered. It simplifies the coding process. The framework has feature-rich coding functions, such as error handling and express middleware. With these advanced functions, your code will be more efficient and bug-free. So, do not wait and take your coding to the next level.

4. Proactive Community Support

ExpressJS provides community support where developers can get assistance whenever needed, making the development process simpler and faster. You can freely get help with your project and contribute to the growing open-source community.

5. Flexible Nature

Now do not let the framework dictate your project’s direction. With ExpressJS’s versatile framework, developers can simply customize their applications. It facilitates content negotiations, dynamic views, flash alteration, and a lot more. Whether it is using unique libraries and tools, you can create a project that suits you.

6. Facilitates Common Script

ExpressJS encourages one common script for multiple applications. It is seamlessly compatible with front-end technologies because of its JavaScript commonality. Several organizations use different frameworks for front-end and back-end whereas ExpressJS offers the best of both worlds at one place. If you are in the business of delivering extensive applications, ExpressJS has a lot to offer.

7. High-performing

When it comes to performance, ExpressJS will never disappoint you. The framework can handle an extensive number of requests without significant downtime or lagging. As a result, you can get satisfied customers and increase revenue.

ExpressJS is a popular JavaScript backend framework that has been embraced by worldwide developers. Its simplicity and personalized experience have made it the de facto choice for building applications with Node.js. Here are some of its robust features that every developer should know about:

1. Routing Capabilities

ExpressJS facilitates robust and flexible routing capabilities. It enables developers to map URL endpoints to a particular functions within their application. It utilizes a refined mechanism of URLs to keep the state of the web application intact. This makes it easier to implement a complicated routing system with minimal coding.

2. Express Middleware functionality

Middleware functionality is one of the core features of ExpressJS. It has made a huge contribution to the growing popularity of the framework. It allows developers to modify the request and response of objects before forwarding them to further middleware functions. It also simplifies features, like logging, authentication, and error handling.

3. Templating Engine Support

ExpressJS allows you to choose from varied templating engines, such as Handlebars, Pug, and EJS to deliver dynamic HTML pages. It also facilitates HTML pages, email templates, and many more.

4. MVC Architecture Support

ExpressJS supports Model-View-Controller (MVC) architecture patterns. It parts the logic into three different layers. As a result, it simplifies the code maintenance and improves reusability.

5. Easy and Flexible API Development

If you want to flexibly build reliable APIs, the ExpressJS framework is one of the best picks. With its strong routing system and middleware capabilities, API creation becomes simpler for developers. As a result, you can create APIs that effortlessly handle complex data.

6. Error Handling Abilities

ExpressJS can facilitate robust error-handling functionality. It can handle synchronous and asynchronous errors. As we know, error handling holds a crucial share in any web application and ExpressJS makes it easier to track and fix bugs.

7. JSON Web Token (JWT) Integration

ExpressJS framework provides easy integration with the JSON web token authentication scheme. It has good security functionality. It is a secure and fast way to verify user identity and allow users to access protected resources.

8. Encourage Scalability and Performance

ExpressJS is designed to be a scalable and fast framework. It is well-suited for developing high-performance applications, supporting lightweight footprints and minimal overhead. It can also handle many requests without crashing or slowing down the application. As a result, you can record high performance and swiftly scale the application.

9. Seamless Compatibility with AngularJS

Express is one of the web frameworks included in the MEAN stack. It seamlessly performs with others, especially with the AngularJS framework. As we know, ExpressJS is a powerful backend technology framework, while AngularJS is a flexible frontend framework that can interact and deliver an exceptional user experience.

Here are the advantages of using ExpressJS to develop an effective web application:

1. ExpressJS is unopinionated which allows us to customize it and use it as per our needs.
2. It is written in JavaScript that utilizes a single language for both front-end and back-end development.
3. It is simple and quick to link with databases, such as MongoDB, MySQL, etc.
4. Express is an open-source framework under the MIT license. It allows you to cut down expenses on tools.
5. It is easy to learn the framework for developers who are already familiar with Node.js architecture.
6. It encourages high-performance web applications by consistently optimizing your code and resources.
7. It is a lightweight and flexible framework, allowing developers to create a custom solution.
8. Express makes it simpler to create APIs.
9. It facilitates rapid development by providing its pre-built functions, such as tools, libraries, and so forth.
10. Express supports robust community support for better performance of the framework. As reported, it has 261 contributors on its GitHub page.

Undoubtedly, ExpressJS is a well-renowned web application framework, but like any other technology, it has its limitations. Let’s understand these challenges and solutions to overcome them.

1. Lack of Structure

ExpressJS does not offer a defined structure for building applications. It can create complexities for developers to manage their code and maintain consistency across different applications.

Solution: Adopting modularization is one of the best practices to organize and develop a consistent structure. Developers can use Express app generators to develop basic structures and then customize them as per requirements.

2. Error-handling

ExpressJS does not offer a built-in approach for error handling that complicates catching and express handle errors effectively.

Solution: Developers can utilize middleware functions to effectively catch and handle errors. In addition, 3rd party error-handling can also work to manage asynchronous errors, including express-async-handler.

3. Lack of Built-in Security

Express does not support built-in security functions, including rate limiting, CSRF protection, and input validation. This can leave applications vulnerable to attacks.

Solution: Using 3rd party security middleware, such as Helmet helps you add security features to their application. In addition, the Implementation of SQL injection can also prevent common attacks.

4. Lack of Real-time Support

Express is not optimized for real-time applications that need instant updates.

Solution: In such a situation, the combination of ExpressJS and a real-time framework, like Socket.io, can work effectively to develop real-time applications.

A constantly evolving ExpressJS framework enables developers to develop web applications ranging from static pages to complex and highly interactive applications. Here are some best practices developed to assist developers build better and more effective applications:

1. Utilize Middleware Judiciously

Middleware is one of the noteworthy features of ExpressJS. It assists developers with custom requests and responses before being handled by the node express server. Express middleware is a useful functionality in implementing new features, therefore it should be utilized judiciously.

Extensive or inappropriate usage of middleware can slow down the application and make debugging more complex.

2. Use A Router for Better Separation of Concerns

Building a complex application with multiple routes increases difficulties to keep the code organized and maintainable. This is where it is suggested to smartly utilize a router to separate the various routes and related logic into different modules. It also encourages the Single Responsibility Principle, allowing each module to focus on a particular set of routes.

3. Implement Error Handling

The accurate way of implementing error handling is integral in every application. As ExpressJS facilitates this robust functionality, allowing explicit and complete control over how errors manifest themselves to users. It not just provides a better experience but assists in tracking and fixing bugs efficiently.

4. Leverage Environmental Variables

Configuration variables, such as database connection strings and API keys, should never be hard coded into your application. Instead, they should be stored in the environmental variables in a way they can be easily modified and secured. As a result, you can see seamless transitions between development, testing, and production environments.

5. Use a Templating Engine

ExpressJS provides a wide array of templating engine options, such as Handlebars, EJS, and Pug. Templates make it simple to manage and render pages that employ some level of dynamism, such as injecting data into a page. Templating engines also allow you to maintain a separation more easily between logic and presentation; increasing readability and maintainability.

6. Performance Optimization

Undoubtedly, ExpressJS is a robust framework, but performance issues might arise due to poor optimization. Therefore, proper optimization is necessary, including employing caching, pre-compressing responses, optimizing database operations, and a lot more. It is suggested to be alerted to avoid bottlenecks and fix them to ensure the best possible experience for your users.

To get started with ExpressJS, it is crucial to understand how this popular web framework works for your application. It will help you better utilize its features and build an exemplary web application for your business.

Let’s take an express.js app example to better understand the process of ExpressJS.

Whenever you create a new project with npm express, you must have a package.json file.

Creation of package.json

A JavaScript Object Notation (JSON) is a file that contains the entire details related to the Express project. It includes several modules, the project name, and much more. But before, you need to create a project directory to first add Express as a module in your project and then the package.json file.

Using this command, a package.json file will be generated in the root of the project directory. Do remember, the package.json file must exist in that directory to install any module from ExpressJS npm.

Installing ExpressJS

Now, you can install Express by using the below-mentioned command:

npm install --save express

To ensure Express has been successfully installed, you have two methods to confirm.

• You will see a new section in package.json with the name of the dependencies file.

• Secondly, a new folder named node_modules is suddenly shown in the root of your project directory. In this folder, all installed packages are locally stored in the project.

Server Building with Express

Now, at the root of the project's directory, we will create the index.js file to create a simple ExpressJS server application using our installed Express framework package.

To turn on the node express server, visit your terminal and enter:

node index.js

This command will start the server, the minute when we call listen on port 3000. Using our browser, we request http://localhost:3000, and our server responds with Hello World, displaying the message in the browser.

You can see the first line of the code mentions requires functionality to integrate the express module.

Using this method, a npm express package is included and used in any JavaScript file in our project. Before moving forward, it is necessary to create an instance of Express for handling server-to-client requests and responses.

In this case, it is considered a variable app.

In an app.get() function, the express server in node.js tells what to do when a get request is made at a given route. There is a callback function (req, res) that alerts the incoming request and responds accordingly using the res response object.

The Express framework provides us with both requests and responses. The req string, arguments, body, and HTTP headers are all represented by the req object, which also has properties for the object's other components. The HTTP response sent by the Express app in response to an HTTP request is represented by the res object. In our scenario, whenever a request is made to the route /, a text message with the word "Hello World" is sent.

Finally, app.listen() initiates a port and host, in this case, the localhost, for the connections to respond to incoming client requests. The port number can be defined, for example, as 3000.

If you are starting your programming journey with ExpressJS, here are some of the basic concepts that can be a great helping hand. Let’s check.

1. Routing

ExpressJS allows developers to define routes for handling incoming requests for various URL paths. The app.get(), app.put(), app.post(), and app.delete() are one of the most common approaches to describe routes that respond to diverse HTTP and URLs. This enables developers to easily map requests to specific functions and customize responses based on user inputs. A good understanding of route parameters and how to handle dynamic URLs is crucial for building scalable and dynamic web applications.

2. Middleware

Middleware functions in ExpressJS are essential for handling requests before they reach the route handler. Middleware can be used to add headers to requests, check authentication, or log incoming requests. Understanding how middleware works and how to use it effectively can help developers build secure and performant web applications.

3. Template Engines

ExpressJS provides support for various template engines like EJS, Pug, and Handlebars. These engines enable developers to create dynamic HTML pages and simplify the process of rendering views. Understanding how to use template engines and modify views based on user data is important for building user-friendly applications.

4. Error Handling

Handling errors effectively is essential for preventing bugs and improving application performance. In ExpressJS, middleware can be used to catch and express handle errors that occur during request processing. It can be defined using the app.use() approach, allowing developers to develop custom error-handling logic for the application. A good understanding of error-handling strategies and best practices can help developers build robust and reliable web applications.

5. Debugging

Debugging is an important part of the development process and understanding the tools and techniques available for debugging ExpressJS applications. It also holds a crucial role in identifying and resolving issues. ExpressJS includes built-in debugging tools using the debug module. As a result, it helps developers to know how to use them effectively to troubleshoot issues.

6. Scaffolding

Scaffolding is a technique used to generate boilerplate code and enable developers to quickly bootstrap new projects. Tools like Express Generator can be used to generate ExpressJS applications with pre-configured settings, layouts, and views. Understanding how to use scaffolding tools can save time and help developers get started on new projects more quickly.

7. Cookies

Cookies are small pieces of data stored on the client side by the server. In ExpressJS, developers can make use of cookies to store session data, user preferences, or other application-specific data. Building applications with cookie-based functionality requires an understanding of how to use middleware to set and read cookies.

8. Sessions

Sessions are a way of maintaining the state across multiple requests in a web application. ExpressJS provides a robust session management system that can be customized to suit the specific needs of an application. Understanding how to configure and manage sessions in ExpressJS is important for building scalable and secure web applications that provide a good user experience.

Are you confused between ExpressJS and NodeJS to build an effective application? Well, it is obvious. Both tools come with their own advanced benefits and features. But choosing one against another is a bit complicated because of their close terms to syntax and use. So, we will help you make an informed decision by comparing both tools.

Let’s start!

The above-mentioned comparison shows that both node.js and express.js have something to deliver in diverse ways that are highly effective and worthwhile. Both tools are well-liked by developers.

Meanwhile, you must determine the best pick as per your business requirement.

Suppose if you are wondering about developing a web app in Node.js, then ExpressJS is one of the best bets. It provides an expansive range of useful features that can simplify and fast your development process.

However, if you are planning to build a different kind of application that does not need web-specific features, then Node.js individually can prove to be beneficial in the development process.

In a tech stack, ExpressJS can be characterized under microframeworks , while Node.js has a place under frameworks (full stack). Therefore, several applications use Node.js, and ExpressJS is the best choice for CTOs to create a minimum viable product (MVP).

According to Enlyft, 88,087 companies are using ExpressJS in their tech stacks, including:

1. Twitter
2. Accenture
3. Kevin
4. Paytm
5. PayPal
6. Uber
7. IBM

Are you on the lookout for the next-gen trends in web development? Then it is the right time to add ExpressJS to your bucket list. This flexible, lightweight, and fast Node.js framework has been gaining huge traction, and for all the right reasons. As per recent reports shared by Built With, 976,367 live websites are using ExpressJS. It witnessed that ExpressJS is the driving force behind the web applications of several businesses.

It makes it easier to build a Node.js web application. Well, the reason behind its popularity is its simplicity and flexible nature. Moreover, several factors come forward to ensure the bright future of the ExpressJS framework. Let’s discover!

1. Easy Learning of Express.js

ExpressJS is a basic web development framework that can be easily learned. Even if you are a newbie programmer, you can simply understand and start working with it. The framework has a simple interface, unlike other frameworks that can be complex to work with.

2. Versatile

ExpressJS can be used for developing an expansive range of web applications from API development, and web application to mobile app development. Its versatile nature makes it the best choice for startups and businesses that are looking to develop an effective web application without spending a lot.

3. Easy to Scale and Grow

Developing applications that need to be scaled is a breeze with ExpressJS. It provides developers with the ability to scale applications with ease, without compromising on performance, and speed. It will prove an ideal fit for businesses looking for opportunities to scale and grow in technology.

4. Large Community Support

With a large and proactive community of developers working worldwide, the framework has an abundance of resources, plugins, and ExpressJS documentation available. These resources make development more comfortable for developers. Moreover, it can assist you solve complex problems quickly.

5. High Performing

Performance holds a heavy share in web development, and ExpressJS excels in this field. Its lightweight nature allows applications to perform better, load fast, and provide better response time. Moreover, it also provides developers with the ability to optimize their applications, improving performance even further.

6. Budget-friendly

If you have a tight budget and are looking for a cost-effective web development solution, ExpressJS is an ideal choice. Being an open-source technology, it is free to use and comes with an expansive range of features. With the help of its features, you can create complex web applications with ease. Most importantly, it assists you to develop projects efficiently and saves you time, money, and effort.

Overall, it has all the features and benefits that establishes it as a next-gen approach to web development. If you are looking for an efficient solution for your next web app development project, consider using ExpressJS as your framework of choice.

On this page, we have touched on the benefits, features, importance, limitations, and a lot more using ExpressJS. Its minimalist approach and freedom of action makes it an attractive alternative to building a web application with ease. The framework is consistently climbing the charts to become a household tool for both professionals and newbies. An enormous number of large-scale organizations, like PayPal, LinkedIn, Yahoo, and many more have been replying to the ExpressJS framework.

As a business owner, you can also develop a next-gen web application by hiring an ExpressJS developer.

Do remember, you can hire seasoned ExpressJS and Node.js developers with Radixweb. At Radixweb, we have enriched experience with ExpressJS and Node.js to build varied projects for our global clients. Our expertise in ExpressJS development helps us to deliver exceptional solutions to our clients across various industries, from e-commerce to healthcare.

Whether you need to build a custom software from scratch or enhance the existing one, Radixweb will be always there to help you.

To learn more about ExpressJS, feel free to contact our experts.

If you have any query or want to share feedback, do let us know in the comments section and we will get back to you as soon as possible.