Node.js

Question 1

What is Node.js?

Answer 1

an asynchronous event-driven JavaScript runtime that’s designed to build scalable network applications

Question 2

What can Node.js be used for?

Answer 2

foundation of a web library or framework

Question 3

What is a REPL?

Answer 3

Read–eval–print loop - a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user

Question 4

When was Node.js created?

Answer 4

2009

Question 5

What back end languages have you heard of?

Answer 5

Python, PHP, Ruby

Question 6

What is a computer process?

Answer 6

the instance of a computer program that is being executed by one or many threads

Question 7

Roughly how many computer processes are running on your host operating system (Task Manager or Activity Monitor)?

Answer 7

100+

Question 8

What is the process object in a Node.js program?

Answer 8

a global variable that provides information about, and control over, the current Node.js process

Question 9

How do you access the process object in a Node.js program?

Answer 9

just use the process variable (it’s global)

Question 10

What is the data type of process.argv in Node.js?

Answer 10

array of strings

Question 11

What is a JavaScript module?

Answer 11

each JavaScript file is a module

Question 12

What values are passed into a Node.js module’s local scope?

Answer 12

exports, require()

Question 13

Give two examples of truly global variables in a Node.js program.

Answer 13

process, console

Question 14

What is the purpose of module.exports in a Node.js module?

Answer 14

to use variables and functionalities from other modules

Question 15

How do you import functionality into a Node.js module from another Node.js module?

Answer 15

require(‘relative file path’)

Question 16

What is the JavaScript Event Loop?

Answer 16

takes the first event from the queue pushes it to the Call Stack

Question 17

What is different between “blocking” and “non-blocking” with respect to how code is executed?

Answer 17

blocking code is executed in sequence – each statement waits for the previous statement to finish before executing
non-blocking code doesn’t have to wait – your program can continue to run

Question 18

What is a directory?

Answer 18

A folder

Question 19

What module does Node.js include for manipulating the file system?

Answer 19

File System (fs)

Question 20

What is a relative file path?

Answer 20

file path from the current working directory

Question 21

What is an absolute file path?

Answer 21

file path from the root directory

root === /

Question 22

What method is available in the Node.js fs module for writing data to a file?

Answer 22

fs.writeFile

Question 23

Are file operations using the fs module synchronous or asynchronous?

Answer 23

both, depends on which one you use