Node

Question 1

What is Node.js?

Answer 1

A program that allows javascript code to run outside of a web browser

Question 2

What can Node.js be used for?

Answer 2

websites and backend services

Question 3

What is a REPL?

Answer 3

(Read Eval Print Loop) is the environment where code can be executed

Question 4

What is a computer process?

Answer 4

The actual execution of a program; a process is an instance of a program

Question 5

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

Answer 5

hundreds

Question 6

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

Answer 6

global object that provides information about the current node.js process

Question 7

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

Answer 7

use the global name process

Question 8

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

Answer 8

array

Question 9

What is a JavaScript module?

Answer 9

a .js file in node.js

Question 10

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

Answer 10

exports, require, module, __filename, __dirname

Question 11

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

Answer 11

process, console

Question 12

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

Answer 12

a way to send data from one module(js file) to another

Question 13

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

Answer 13

using the require function

Question 14

What is the JavaScript Event Loop?

Answer 14

it runs asynchronous code separate from the call stack that does not block the normal flow of code

Question 15

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

Answer 15

blocking is code that prevents further code from running until the current task is completed, non-blocking is asynchronous

Question 16

What is a directory?

Answer 16

a location that holds files

Question 17

What is a relative file path?

Answer 17

relative path do not start with /, but ‘..’

Question 18

What is an absolute file path?

Answer 18

absolute path starts with / and point to the root

Question 19

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

Answer 19

‘fs’ module

Question 20

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

Answer 20

fs.writeFile()

Question 21

Are file operations using the fs module synchronous or asynchronous?

Answer 21

.

Question 22

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

Answer 22

writeFile()

Question 23

Are file operations using the fs module synchronous or asynchronous?

Answer 23

both

Question 24

What is JSON?

Answer 24

data interchange form, with data type string

Question 25

What are serialization and deserialization?

Answer 25

Serialization is a process of converting an Object into stream of bytes so that it can be transferred over a network or stored in a persistent storage.

Question 26

How to you serialize data into a JSON string using JavaScript?

Answer 26

JSON.stringify()

Question 27

How do you deserialize a JSON string using JavaScript?

Answer 27

JSON.parse()