Node.js Core Modules & Event Loop

Question 1

What is the event loop in Node.js?

Accepted Answer

A mechanism that handles asynchronous operations by executing callbacks when I/O operations complete

Answer

A for loop that iterates over DOM events

Answer

A browser API for handling click events

Answer

A database query optimization technique

Question 2

What is the purpose of the 'fs' module in Node.js?

Accepted Answer

To interact with the file system for reading, writing, and manipulating files

Answer

To format strings for display output

Answer

To manage font styles in HTML output

Answer

To filter and sort array elements

Question 3

What is the difference between 'process.nextTick()' and 'setImmediate()' in Node.js?

Accepted Answer

process.nextTick() executes before any I/O events; setImmediate() executes after the current I/O poll phase

Answer

They are identical functions with different names

Answer

setImmediate() always runs first

Answer

process.nextTick() is deprecated in favor of setImmediate()

Question 4

What does 'require()' do in Node.js?

Accepted Answer

Imports and caches a module, returning its exports

Answer

Creates a new HTTP request to an external API

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Declares a required parameter for a function

Answer

Installs a package from npm

Question 5

What is the Buffer class used for in Node.js?

Accepted Answer

To handle binary data directly without converting to strings

Answer

To buffer user interface updates in the browser

Answer

To create HTML form input buffers

Answer

To manage database connection pools

Question 6

What are Streams in Node.js and why are they important?

Accepted Answer

Objects that enable reading or writing data in chunks, reducing memory usage for large datasets

Answer

CSS animation sequences rendered on the server

Answer

Database query result sets stored in arrays

Answer

Video streaming services built with Node.js