Node.js

Question 1

What is a CLI?

What is a GUI?

Answer 1

command line interface

graphical user interface

Question 2

Give at least one use case for each of the commands listed in this exercise.
man
cat
ls
pwd
echo
touch
mkdir
mv
rm
cp

Answer 2

man - manual
cat - read files and “concatenate files”
ls - list files – options -aF to show all and any files starting with .
pwd - print working directory
echo - echos a string
touch - alters a file or directory - make blank file
mkdir - make directory – options -p to include parent directories
mv - move or rename files
rm - remove files –> rm -r remove directory -f force
cp - copy file

Question 3

What is Node.js?

Answer 3

asynchronous event-driven JavaScript runtime

Question 4

What can Node.js be used for?

Answer 4

used for server-side programming, and primarily deployed for non-blocking, event-driven servers, such as traditional web sites and back-end API services

Question 5

What is a REPL?

Answer 5

read, evaluate, print, loop

where you can do calculations and stuff in a ‘terminal’

Question 6

When was Node.js created?

Answer 6

2009

Question 7

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

Answer 7

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

Question 8

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

Answer 8

type process in node command

Question 9

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

Answer 9

strings in an array

–> string array

Question 10

What is a JavaScript module?

Answer 10

smaller JS files that do a specific thing and put together to do “somethign” as a whole

Question 11

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

Answer 11

exports, require, module, __filename, __dirname

Question 12

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

Answer 12

process and global, console

Question 13

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

Answer 13

allows the function to be import as module using require

Question 14

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

Answer 14

require()

Question 15

What is the JavaScript Event Loop?

Answer 15

consists of stack, heap, and queue

code is put through a stack and uses last in first out to return functions/modules, if there is any async functions/ http requests then it goes to the heap and then once it checks out it goes to the queue. Once the stack is empty it then puts the first item from the queue to the stack then returns it

Question 16

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

Answer 16

blocking is when code “blocks” the other code because the compiler waits until that blocker code completes,

non-blocking is when code runs async and gets placed on a heap then a queue to return once a stack is cleared

Question 17

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

Answer 17

.readFile

Question 18

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

Answer 18

fs.writeFile

Question 19

Are file operations using the fs module synchronous or asynchronous?

Answer 19

async

Question 20

npm stands for

Answer 20

node package manager

Question 21

what is a package

Answer 21

directory with files with a package json

Question 22

How can you create a package.json with npm?

Answer 22

npm init –yes

Question 23

What is a dependency and how to you add one to a package?

What happens when you add a dependency to a package with npm?

Answer 23

a dependency is a code that project needs and “depends on” like a library if you use MATH.__()

you can add to a package using npm install “package”

when a dependency gets added it is added to package.json