Express web framework Node js JavaScript Learn web development MDN

We’ll talk more about the generated app when we get to the article on generating a skeleton application. There are many releases of Node — newer releases contain bug fixes, support for more recent versions of ECMAScript standards, and improvements to the Node APIs. Guided Project instructors are subject matter experts who have experience in the skill, tool or domain of their project and are passionate about sharing their knowledge to impact millions of learners around the world. To achieve this, you will be taking on the role of helping a friend create a website for their pizzeria using Node.js. In order to be successful in this project, you will need some experience with Node.js, HTML, and CSS. Out of what’s called Callback Hell, or the situation we find ourselves in when nesting callbacks within callbacks.

node.js web development

The Node.js runtime keeps track of the stack context leading to this callback function, and eventually an event will fire causing this callback function to be called. Specifically, you saw that JavaScript has a life outside web browsers and that Node.js is an excellent programming platform with many interesting attributes. While it is a relatively young project, Node.js has become very popular and is widely used not just for web applications but for command-line developer tools and much more. Because the Node.js platform is based on Chrome’s V8 JavaScript engine, the project has been able to keep up with the rapid improvements to the JavaScript language. With both the callback functions and the promise’s asynchronous coding, Node.js had its own complexity issue.


You’ve also seen how npm can be used to import Express into an application, and also how you can create applications using the Express Application Generator tool and then run them. Typically we instead manage dependencies using a plain-text definition file named package.json. The package.json file should contain everything npm needs to fetch and run your application .

Improvement and improvisation in are always taken into consideration. That’s why they have a good intention to find their way to launch new releases and enhances the standards of its codes and features. With ES6 Spec for JavaScript and the support of an open source community, Node.js technology will develop more and become more innovative in the future. Thanks to V8 JavaScript engine, Node.js Web Development process is more efficient along with its assurance about quality and security. As I mentioned before, non-blocking I/O operation of Node.js application is the main factor that makes ‘lightweight and scalable’ to be the character of your application. The extension of the file being requested will be parsed and lower-cased.


With Node.js, we are finally able to implement applications with the same programming language on the client and server by having JavaScript at both ends of the web, in the browser and server. About Node.jsJavaScript is at the fingertips of every frontend web developer, making it a very popular programming language, so much so that it is stereotyped as being for client-side code in web pages. The chances are that, having picked up this book, you’ve heard of Node.js, a programming platform for coding in JavaScript outside web browsers. Now about ten years old, Node.js is becoming a mature programming platform that’s widely used in projects both big and small.

node.js web development

It is more noteworthy that Node.js is an excellent platform for the data-intensive real-time application that runs across distributed devices. It is also specifically designed for writing scalable Internet applications, prominently in developing web servers. Its remarkable performance is proved based on the architecture of many Internet applications. VS Code uses TypeScript type declaration files (for example node.d.ts) to provide metadata to VS Code about the JavaScript based frameworks you are consuming in your application. Type declaration files are written in TypeScript so they can express the data types of parameters and functions, allowing VS Code to provide a rich IntelliSense experience. Thanks to a feature called Automatic Type Acquisition, you do not have to worry about downloading these type declaration files, VS Code will install them automatically for you.

Express web framework (Node.js/JavaScript)

JavaScript is a widely-used programming language that gives behavior to web pages. It is a platform that has extended the application of JavaScript code to server side-activity to make it a programming language that can be used both at the front-end and back-end. Writing the server-side applications in JavaScript gives Node JS developers the chance to use the same language on the front-end and back-end, giving it the status of full-stack. Due to this, they don’t need to use an additional server-side programming language. Also, it means that there is no need to hire a different developer for the front-end and back-end. You now have a Node development environment up and running on your computer that can be used for creating Express web applications.

  • The createServer() method of http creates a new HTTP server and returns it.
  • You can run Node.js directly from there and avoid switching out of VS Code while running command-line tools.
  • A lot is buried under the covers of the async/await feature, and we’ll be covering this model extensively throughout this book.
  • To explain a little further, eslint src/js is a command that we could enter in our terminal/command line to run eslint on JavaScript files contained in the src/js directory inside our app directory.
  • Moreover, some unproductive modules can be cancelled at the same time you do below things.
  • Before getting to the code, we must consider what Node.js is and how it fits in the overall marketplace of software development tools.

Using non-blocking asynchronous APIs is even more important on Node than in the browser because Node is a single-threaded event-driven execution environment. “Single threaded” means that all requests to the server are run on the same thread . This was an important insight on Ryan Dahl’s part, and is what propelled Node.js’s popularity. Certain actions take a long time to run, such as database queries, and should not be treated the same as operations that quickly retrieve data from memory. Because of the nature of the JavaScript language, Node.js had to express this asynchronous coding construct in an unnatural way. The results do not appear at the next line of code, but instead appear within this callback function.

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Just because that complexity is hidden within Spring and Java EE does not mean that there is no complexity and overhead. By converting blocking function calls into asynchronous code execution, you can configure the systems so that it issues an event when the blocking request is satisfied. The V8 engine is adopting these new features quickly to advance the state of web development.

Of course, the program pauses at that point while the database layer sends the query to the database, which determines the result and returns the data. Depending on the query, that pause can be quite long; well, a few milliseconds, which is an eon in computer time. This pause is bad because that execution thread can do nothing while waiting for the result to arrive. If instead, your application is running on a thread-based server platform, a thread context switch is required to satisfy any other requests that arrive. The greater the number of outstanding connections to the server, the greater the number of thread context switches.

Web Applications

Node.js is a free, open-sourced, cross-platform JavaScript run-time environment that lets developers write command line tools and server-side scripts outside of a browser. The TypeScript language is an interesting offshoot of the JavaScript environment. Because JavaScript is increasingly able to be used for complex applications, it is increasingly useful for the compiler to help catch programming errors. Enterprise programmers in other languages, such as Java, are accustomed to strong type checking as a way of preventing certain classes of bugs.

node.js web development

In addition to defining and fetching dependencies you can also define named scripts in your package.json files and call npm to execute them with the run-script command. This approach is commonly used to automate running tests and parts of the development or build toolchain (e.g., running tools to minify JavaScript, shrink images, LINT/analyze your code, etc.). Specifically, you saw that JavaScript has a life outside web browsers and you learned about the difference between asynchronous and blocking I/O. We then covered the attributes of Node.js and where it fits in the overall web application platform market and threaded versus asynchronous software. Lastly, we saw the advantages of fast event-driven asynchronous I/O, coupled with a language with great support for anonymous closures.

Node.js tutorial in Visual Studio Code

A lot is buried under the covers of the async/await feature, and we’ll be covering this model extensively throughout the book. The original Node.js paradigm delivered the dispatched event to an anonymous function. Now that JavaScript has async functions, node.js web development the Node.js paradigm is shifting to deliver results and errors via a promise that is handled by the await keyword. When an asynchronous function is called, control quickly passes to the event loop rather than causing Node.js to block.

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