Top 12 Node.js Interview Questions & Answers

Node.js is a popular server-side platform which is now more and more organizations are using it. If you are a student or a node js developer and want to prepare for the career change for which you have any upcoming interview of node.js, it is always suggested to brush up and prepare for the interview beforehand. There are few commonly asked Node.js interview questions that asked in any type of interviews. Here, we have compiled a comprehensive list of node js interview question pdf file along with answers that come up often in interviews and the best ways to answer these questions. It will also help you to understand the basic concepts of node.js.

Node.js is an open-source cross-platform JavaScript runtime environment and library to run web applications outside the browser of the client. It is mainly used for creating server-side web applications. This server-side scripting is used to build scalable programs.

Node.js is ideal for data-intensive applications because it uses asynchronous event driving model. It has multiple advantages over any other server-side languages, the well-known being non-blocking I/O. You can also use it for developing real-time web applications, general purpose applications, network applications and distributed systems.

Node.js works on V8 environment. Vode.js is a virtual machine which uses JavaScript as its scripting language and can achieve high output via non-blocking I/O and single threaded event loop.

Node.js use to make building scalable network programs easily. Some of its added advantages are:

• It hardly ever blocks
• It is usually fast
• It provides unified programming language as well as data type
• It capitulate huge concurrency.  

Everything here is asynchronous.

For the async processing, node.js is single threaded. After doing async processing on a single thread under the typical web loads, more scalability along with high performance can be achieved instead of the typical thread-based implementation.

I/O is the short form of Input and Output. It can access anything outside of your application. It will be loaded into the machine memory to run the program once application gets started.

The Node js developer can use Node.js on the following purpose:

• Network applications
• Web applications (mainly real-time web apps)
• General purpose applications

Distributed Systems

As per the computer programming, event-driven programming is a paradigm programming in which the flow of the program can be determined through events like messages from any threads or programs. It is an application architecture technique which has been split into two parts: 1. Event Solution 2. Event Handling

It is a generic piece of code that runs between several asynchronous functions.

There are two different types of API functions:

Synchronous Blocking Functions

Asynchronous Non-blocking Functions

A callback function is called after a given task. It permits other code to be run in the mean time and also stops the blocking. Being an asynchronous platform, Node.js is heavily relies on callback. All APIs of Node.js has been written to support Callbacks.

NPM or Node Package Manager is responsible for managing all the modules and packages for Node.js

NPM provides two main functionalities:

• Offers online repositories for node.js modules/packages that are searchable on search.nodejs.org

Provides command-line utility to install Node.js packages and also manages Node.js versions and dependencies.

MongoDB is the common database used with Node.js. It is a cross-platform, NoSQL, document oriented database which can provide high performance, easy scalability and high availability.