Node.js

Question 1

What is a CLI?

Answer 1

Command-line interfaces

Processes commands to a computer program in the form of lines of text

Question 2

What is a GUI?

Answer 2

Graphical user interface

Allows users to interact with electronic devices through graphical icons and audio indicators

Question 3

Give at least one use case for each of the commands listed in this exercise.

Answer 3

man - To look up command information
cat - Print contents of files to see what they are
ls - See a list of the contents in a directory
pwd - To see the current working directory
echo - Kind of like console.logging. To see the status of something?
touch - To set the access date or modify a date of a file/directory
- *To create files
mkdir - To create directories
mv - To rename a file or directory
- To move a file/directory, because renaming something technically changes location
rm - To delete a file/directory
cp - To copy something, kind of like “save as” in programs

Question 4

What are the three virtues of a great programmer?

Answer 4

Laziness, impatience, hubris

Question 5

What is Node.js?

Answer 5

A program that allows JavaScript to be run outside of a web browser.
Commonly used to build back ends for Web applications, command-line programs, or any kind of automation that developers wish to perform.

Question 6

What can Node.js be used for?

Answer 6

Build scalable network applications

Single-threaded event loop model

Question 7

What is a REPL?

Answer 7

Read-eval-print loop or language shell
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.
(browser console)

Question 8

When was Node.js created?

Answer 8

2009, by Ryan Dahl

Question 9

What back end languages have you heard of?

Answer 9

Python, Elixir, ruby, PHP, SQL, Java, C++, Go, C#, JavaScript, VBA, Clojure, C, Julia, Haskell, Pascal, Rust, Lisp, Perl, TypeScript, Objective-C, Swift, Kotlin, Scala
*PHP, Ruby, Python, JavaScript, Perl - very similar, just know for the job interviews or something. “What is the diff between javascript vs java
Javascript is the only one with event loop

Question 10

What is a computer process?

Answer 10

The instance of a computer program that is being executed by one or many threads
It contains the program code and its activity.

Question 11

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

Answer 11

Like 100 or more

Question 12

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

Answer 12

Because FSWB is based on making multiple processes work together to form one application, so having at least a cursory awareness of computer processes is necessary.
This will be extremely important when learning about applications made of multiple components, such as clients, servers, and databases.

Question 13

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

Answer 13

A global that provides information about, and control over, the current Node.js process. As a global, it is always available to Node.js applications without using require(). It can also be explicitly accessed using require().

Question 14

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

Answer 14

console. log(?)

* can just pull it out of thin air

Question 15

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

Answer 15

It returns an array containing the command-line arguments passed when the Node.js process was launched.
*Array of strings

Question 16

What is a JavaScript module?

Answer 16

A single .js file

Question 17

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

Answer 17

\_\_dirname
\_\_filename
Exports
Module
require(id)

Question 18

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

Answer 18

AbortController

AbortSignal

Question 19

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

Answer 19

To allow the module to be an instance. It’s what allows these files to be used by assigning them to the module.exports object.
* if you want to make something available within a separate program, is to export it. We take our value/function/, etc, assign it to module.exports. So we can call it in another module.

Question 20

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

Answer 20

By assigning the module to the module.exports object and calling it in the require function…?
* require(‘./add’)

Question 21

What is a directory?

Answer 21

Collection of files created for organizational purposes

Question 22

What is a relative file path?

Answer 22

Location that is relative to a current directory

Question 23

What is an absolute file path?

Answer 23

Always contains the root element and the complete directory list required to locate the file

Question 24

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

Answer 24

‘fs’

Question 25

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

Answer 25

fs. write()

* writeFile method

Question 26

Are file operations using the fs module synchronous or asynchronous?

Answer 26

Asynchronous…?
*both, fs module has both synchronous and asynchronous