Cover image for JavaScript Concepts A Node.js Developer Should Know

JavaScript Concepts A Node.js Developer Should Know

jessicabennett profile image Jessica Bennett ・4 min read

JavaScript is the most widespread language for web page development. This is why it is often called the “language of the web”.

Almost every contemporary web browsers support this language. At runtime, this high-level dynamic programming language gets interpreted by the client browser. Using JavaScript, web developers add interactive elements to their websites and make it impressive.

You know how big the WWW content development is! Other than HTML and CSS, this JavaScript language is the third core technology that has been used here. Most of its syntax has been derived from the C language. 

Well, in earlier days, for scripting the client-side, developers preferred to use JavaScript. When Node.js came into the picture, it was all set to be used for server-side development as well. Node JS is built on the JSV8 engine that is powered by Google. It is a cross-platform, powerful, JavaScript-based runtime framework. Being a completely free platform, Node.js instantly became one of the most favored frameworks to the developers. 

This article is going to highlight the key concepts that a Node.js programmer should know.

Asynchronous or Non-blocking I/O 

Being a server-side framework, one of the main operations of Node.js is to handle all the browser requests efficiently. Well, Node.js does not follow the traditional principle of I/O. Here’s how the Node.js architecture works. 

Source: https://twitter.com/

When a request takes longer time, Node.js sends it in the event loop and moves to call stack to attend the next request. The moment the pending request is done processing, the response is rendered on the browser.

Check out the following dummy example to understand this better.

Source: https://simpleprogrammer.com


Have you worked with packages in Java? If yes, then you will find no difference at all with the modules in Node.js.

Modules are simple JavaScript files that contain specific purpose-oriented code. Here the module pattern is used for making the code easier to work with and navigate. You have to ‘require’ a module property in a JavaScript file to use it. Node.js works with two types of modules.

  • Core modules

Core modules are pre-compiled and are available in the Node.js library. The main objective of these modules is to save the developers from the tedious task of writing repetitive codes. Some of the common core modules are URL, HTTP, FILE SYSTEM, EVENTS, etc. 

  • User-defined modules 

Every application is built to meet certain objectives or goals. Sometimes the core modules are not enough to fulfill the desired functionality. This is when developers need user-defined modules. 

Check out the image below for better understanding.

Source: https://simpleprogrammer.com


While working with Node.js, you need to use prototypes quite frequently. Hence, having a good grasp on this prototype concept of JavaScript is necessary to work seamlessly with Node.js. 

JavaScript does not have the concept of classes like other programming languages C++ or Java. First, you need to create an object in JavaScript. Now, you can either augment your object or create new objects from it. This process is known as prototypal inheritance

Check out the following sample code to understand it better.

Source: https://simpleprogrammer.com


Callbacks are the most widely used functional programming paradigm. These anonymous functions in JavaScript are passed as arguments to other functions. Also, these can be executed or returned from that function to be executed later.

When a callback function is passed as an argument to another function, only the function definition is passed. The timing of the callback function execution entirely depends on the calling function’s mechanism. This is the sole basis of the asynchronous or non-blocking behavior of the Node JS framework. 

Source: https://simpleprogrammer.com

Being a leading Node.js development company and having 10+ years of industry experience to work on diverse projects, we think that every Node.js programmer should have a good grasp on these four JavaScript concepts. Well, along with these four, some other concepts that a good Node.js developer should know are

  • Aspect-oriented programming
  • Streams
  • Events
  • Closures

Do you have a project in your mind? Thinking of getting Node.js development services? Well, you can reach our professional consultant team and can hire Node.js developer with expertise in industry best practices.

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jessicabennett profile

Jessica Bennett


Hi! I am Jessica, a Marketer and Research Writer by background. I take interest in latest web and mobile app development trends and technologies.


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Hmmm...It's really cool material especially in couple with this guide. Thank you very much!