Node

Question 1

What is Node.js?

Answer 1

Node.js is a program that allows JavaScript to be run outside of a web browser.
It is commonly used to build back ends for Web applications, command-line programs, or any kind of automation that developers wish to perform. Node.js is powered by V8; the same JavaScript engine in the Google Chrome browser.

Question 2

What can Node.js be used for?

Answer 2

back ends for Web applications, command-line programs, or any kind of automation that developers wish to perform

Question 3

What is a REPL?

Answer 3

read–eval–print loop
simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user; a program written in a REPL environment is executed piecewise.

Question 4

When was Node.js created?

Answer 4

2009 by Ryan Dahl

Question 5

What back end languages have you heard of?

Answer 5

Ruby, PHP, Java, . Net, and Python

Question 6

What is a computer process?

Answer 6

a process is 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

A lot

Question 8

Why should a full stack Web developer know that computer processes exist?

Question 9

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

Answer 9

The process object is a global that provides information about, the current Node.js process

Question 10

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

Answer 10

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

It can also be explicitly accessed using require()

const process = require(‘process’);

Question 11

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

Answer 11

an array

Question 12

What is a JavaScript module?

Answer 12

It’s a single .js file

Question 13

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

Answer 13

exports, require, module, __filename, __dirname

Question 14

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

Answer 14

console object,
setInterval
process
global

Question 15

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

Answer 15

to achieve modular programming. Modular programming refers to separating the functionality of a program into independent, interchangeable modules, such that each contains everything necessary to execute only one aspect of the desired functionality.

Question 16

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

Answer 16

const add = require(‘./add’);

Question 17

What is the JavaScript Event Loop?

Answer 17

a constantly running process that monitors both the callback queue and the call stack

Question 18

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

Answer 18

A blocking assignment takes effect immediately it is processed. A nonblocking assignment takes place at the end of processing the current “time delta”

Question 19

What is a directory?

Answer 19

file system cataloging structure, folder

Question 20

What is a relative file path?

Answer 20

the hierarchical path that locates a file or folder on a file system starting from the current directory. relative from current directory

Question 21

What is an absolute file path?

Answer 21

locates the file or folder starting from the root of the file system.

Question 22

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

Question 23

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

Answer 23

writeFile()

Question 24

Are file operations using the fs module synchronous or asynchronous?

Answer 24

asynchronous