NodeJS is an open-source and cross-platform runtime environment developed on Chrome’s V8 JavaScript engine for performing JavaScript code beyond an internet browser. You require to remember that NodeJS isn’t a structure, and it’s not a programing language. It supplies an event-driven, non-blocking (asynchronous) I/O and cross-platform runtime environment for constructing extremely scalable server-side applications utilizing JavaScript.
NodeJS Interview Questions & & Responses
We have actually currently developed Fundamental Level NodeJS Interview Questions and Responses– Set 1
This set consists of the intermediate-level concerns asked in the interview.
1. What is event-driven shows in Node.js?
Event-driven shows is utilized to integrate the event of several occasions and to make the program as easy as possible. The fundamental elements of an Event-Driven Program are:
- A callback function (called an occasion handler) is called when an occasion is set off.
- An occasion loop that listens for occasion activates and calls the matching occasion handler for that occasion.
2. What is buffer in Node.js?
The Buffer class in Node.js is utilized to carry out operations on raw binary information. Typically, Buffer describes the specific memory place in memory. Buffer and selection have some resemblances, however the distinction is selection can be any type, and it can be resizable. Buffers just handle binary information, and it can not be resizable. Each integer in a buffer represents a byte. console.log() function is utilized to print the Buffer circumstances.
3. What are streams in Node.js?
Streams are a kind of data-handling approach and are utilized to check out or compose input into output sequentially. Streams are utilized to deal with reading/writing files or exchanging info in an effective method. The stream module supplies an API for carrying out the stream user interface. Examples of the stream things in Node.js can be a demand to an HTTP server and process.stdout are both stream circumstances.
4. Explain crypto module in Node.js
The crypto module is utilized for securing, decrypting, or hashing any kind of information. This file encryption and decryption essentially assist to protect and include a layer of authentication to the information. The primary usage case of the crypto module is to transform the plain legible text to an encrypted format and decrypt it when needed.
5. What is callback hell?
Callback hell is a problem triggered due to an embedded callback. This triggers the code to appear like a pyramid and makes it not able to check out To conquer this scenario we utilize pledges.
6. Discuss using timers module in Node.js?
The Timers module in Node.js consists of numerous functions that enable us to carry out a block of code or a function after a set amount of time. The Timers module is worldwide, we do not require to utilize need() to import it.
It has the following techniques:
7. Distinction in between setImmediate() and process.nextTick()
The process.nextTick() approach is utilized to include a brand-new callback function at the start of the next occasion line. it is called prior to the occasion is processed. The setImmediate is called at the check stage of the next occasion line. It is developed in the survey stage and is conjured up throughout the check stage.
8. What is the distinction in between setTimeout() and setImmediate() approach?
The setImmediate function is utilized to carry out a specific script right away whereas the setTimeout function is utilized to hold a function and perform it after a given amount of time.
9. What is the distinction in between generate() and fork() approach?
Both these techniques are utilized to develop brand-new kid processes the only distinction in between them is that generate() approach produces a brand-new function that Node ranges from the command line whereas fork() function produces a circumstances of the existing fork() approach and produces several employees to carry out on the exact same job.
10. Discuss using passport module in Node.js
The passport module is utilized for including authentication functions to our site or web app. It executes authentication step which assists to carry out sign-in operations.
11. What is fork in Node.js?
Fork is an approach in Node.js that is utilized to develop kid procedures. It assists to deal with the increasing work. It produces a brand-new circumstances of the engine which makes it possible for several procedures to run the code.
12. What are the 3 techniques to prevent callback hell?
The 3 techniques to prevent callback hell are:
- Utilizing async/await()
- Utilizing pledges
- Utilizing generators
13. What is body-parser in Node.js?
Body-parser is the Node.js body-parsing middleware. It is accountable for parsing the inbound demand bodies in a middleware prior to you manage it. It is an NPM module that processes information sent out in HTTP demands.
14. What is CORS in Node.js?
The word CORS represents “Cross-Origin Resource Sharing”. Cross-Origin Resource Sharing is an HTTP-header based system executed by the internet browser which permits a server or an API to show any origins (various in regards to procedure, hostname, or port) aside from its origin from which the unidentified origin gets consent to gain access to and load resources. The cors plan offered in the npm computer registry is utilized to take on CORS mistakes in a Node.js application.
15. Discuss the tls module in Node.js?
The tls module supplies an application of the Transportation Layer Security (TLS) and Protect Socket Layer (SSL) procedures that are developed on top of OpenSSL. It assists to develop a protected connection on the network.
16. What is using url module in Node.js?
In Node.js url module is utilized to divide the URL of the site into parts so that it ends up being legible and can be utilized in the various parts of the application. The parse() approach is utilized with the url module to separate the URL of the site into parts.
17. What is REST API?
Representational State Transfer (REST) is an architectural design that specifies a set of restrictions to be utilized for producing web services. REST API is a method of accessing web services in an easy and versatile method without having any processing. It works after the demand is sent out from the customer to the server in the type of a web URL as HTTP GET or POST or PUT or erase demand. After that, an action returns from the server in the type of a resource which can be anything like HTML, XML, Image, or JSON. Today JSON is the most popular format being utilized in Web Providers.
18. Discuss the engine Google utilizes for Node.js?
The engine utilized by Google for Node.js is V8. It is one the fastest engine as it is composed in C++. It supplies a runtime environment for the execution of JavaScript code. The very best part is that the JavaScript engine is entirely independent of the internet browser in which it runs. It has a big neighborhood and is extremely portable.
19. Call the tool utilized for composing constant code?
ESLint is a tool utilized in lots of IDEs to compose constant code designs. ESLint is composed utilizing Node.js to supply a quick runtime environment and simple setup by means of npm.
20. What are the various type of HTTP demands?
The most frequently utilized HTTP demands are:
- GET: This demand is utilized to read/retrieve information from a web server. GET returns an HTTP status code of 200 (OK) if the information is effectively recovered from the server.
- PUT: This demand is utilized to customize the information on the server. It changes the whole material at a specific place with information that is passed in the body payload. If there are no resources that match the demand, it will create one.
- POST: This demand is utilized to send out information (file, form information, and so on) to the server. On effective production, it returns an HTTP status code of 201.
- ERASE: This demand is utilized to erase the information on the server at a defined place.
Last Upgraded:
07 Jun, 2023
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