Altimetrik – Node JS Interview Questions

Here is the list of Node JS Interview Questions which are recently asked in Altimetrik company. These questions are included for both Freshers and Experienced professionals. Our Node JS Training has Answered all the below Questions.

1. Differentiate between readFile vs createReadStream in Node.js?

readfile loads the whole file into the memory you pointed out, the fs. createReadStreamreads the entire file in chunks of sizes that you specified. The client will also receive the data faster with fs. createReadStream since it is sent in chunks while it's being read.

2. List down the various timing features of Node.js.

Callback parameter holds the function that to be executed.
Delayparameter holds the number of milliseconds to wait before calling the callback function.
Argsparameter holds the optional parameter.

3. Explain the concept of Punycode in Node.js?

Punycode is an encoding syntax which is used to convert Unicode (UTF-8) string of characters to basic ASCII string of characters. Since host names only understand ASCII characters so Punycode is used. It is used as an internationalized domain name (IDN or IDNA).

4. Differentiate between Node.js vs Ajax?

The difference between Node JS and Ajax is that, Ajax is a client side technology, often used for updating the contents of the page without refreshing it.

5. Does Node.js provide any Debugger?

The Node JS debugger client is not a full-featured debugger but simple step and inspection are possible. The repl command allows code to be evaluated remotely. The next command steps to the next line.

6. Describe the exit codes of Node.js.

Node normally exits with code 0 when no more async operations are pending. process. exit(1) should be used to exit with a failure code

7. What do you understand by an Event Emitter in Node.js?

Node JS allows to create and handle custom events easily by using events module. Event module includes EventEmitter class which can be used to raise and handle custom events.

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8. Is cryptography supported in Node.js?

The Node JS Crypto module supports cryptography and provides cryptographic functionality that includes a set of wrappers for open SSL's hash HMAC, cipher, decipher, sign and verify functions.

9. What is Node.js? Where can you use it?

Node JS is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices. It is primarily used for non-blocking, event-driven servers, due to its single-threaded nature.

10. Why use Node.js?

Node JS is employed as a server-side proxy where it can handle a large amount of simultaneous connections in a non-blocking manner. It is useful for proxying different services with different response times, or collecting data from multiple source points.

11. What are the features of Node.js?

Features of Node JS

Asynchronous and Event
Very Fast
Single Threaded but Highly Scalable
No Buffering and License

12. How do you update NPM to a new version in Node.js?

To check the NPM version use npm version or node --version . If you prefer CLI, to update NPM use npm install -g npm and then npm install -g node.

13. Why is Node.js Single-threaded?

Node JS follows Single-Threaded with Event Loop Model inspired by JavaScript Event-based model with JavaScript callback mechanism. So, It is single-threaded similar to JavaScript but not purely JavaScript code which implies things that are done asynchronously like network calls, file system tasks, DNS lookup, etc.

14. Explain the role of REPL in Node.js.

REPL (READ, EVAL, PRINT, LOOP) is a computer environment similar to Shell (Unix/Linux) and command prompt and is useful in writing and debugging the codes. Node comes with the REPL environment when it is installed. System interacts with the user through outputs of commands/expressions used.

15. Name the types of API functions in Node.js.

The two types of API functions in Node JS are: Asynchronous, non-blocking functions. Synchronous, blocking functions.

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TOP MNC's NODE JS INTERVIEW QUESTIONS & ANSWERS

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Altimetrik Node JS Interview Questions