Command Line / Node.js

Question 1

What is a CLI?

Answer 1

Command-line interface - a form of user interface that processes commands to a computer program in the form of lines of text

Question 2

What is a GUI?

Answer 2

Graphical user interface - a form of user interface that allows users to interact with electronic devices through graphical icons instead of text-based user interfaces

Question 3

What does the man command do?

Answer 3

displays manual for command information

Question 4

What does the cat command do?

Answer 4

concatenate files and prints to the command prompt

Question 5

What does the ls command do?

Answer 5

list directory contents

Question 6

What does the pwd command do?

Answer 6

print name of the current/working directory

Question 7

What does the echo command do?

Answer 7

display a line of text

Question 8

What does the touch command do?

Answer 8

create an empty file; change file timestamps

Question 9

What does the mkdir command do?

Answer 9

make directories

Question 10

What does the mv command do?

Answer 10

move/rename files or directories

Question 11

What does the rm command do?

Answer 11

remove files or directories

Question 12

What does the cp command do?

Answer 12

copy files and directories

Question 13

What are the three virtues of a great programmer?

Answer 13

laziness, impatience, hubris

Question 14

What is Node.js?

Answer 14

a program that allows JavaScript to be run outside of a web browser

Question 15

What can Node.js be used for?

Answer 15

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

Question 16

What is a REPL?

Answer 16

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 17

When was Node.js created?

Answer 17

2009

Question 18

What back end languages have you heard of?

Answer 18

Python, Ruby, Java, PHP

Question 19

What is a computer process?

Answer 19

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

Question 20

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

Answer 20

8

Question 21

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

Answer 21

Full stack Web development is based on making multiple processes work together to form one application

Question 22

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

Answer 22

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

Question 23

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

Answer 23

just type process

Question 24

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

Answer 24

array

Question 25

What is a JavaScript module?

Answer 25

a single .js file

Question 26

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

Answer 26

__dirname, __filename, exports, module, require( )

Question 27

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

Answer 27

console, process

Question 28

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

Answer 28

functions can be assigned to module.exports - makes them available to other modules by calling require( )

Question 29

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

Answer 29

const variableName = require( ‘./fileName );

Question 30

What is the JavaScript Event Loop?

Answer 30

a concurrency model that is responsible for executing the code, collecting and processing events, and executing queued sub-tasks

Question 31

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

Answer 31

blocking code sits on the stack until it is executed, while non-blocking code is pushed off onto the task queue to be executed later

Question 32

What is a directory?

Answer 32

structure of a file system that stores files

Question 33

What is a relative file path?

Answer 33

location of a file/directory relative to the current file/directory

Question 34

What is an absolute file path?

Answer 34

full URL to a file

Question 35

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

Answer 35

fs.writeFile( )

Question 36

Are file operations using the fs module synchronous or asynchronous?

Answer 36

asynchronous (unless explicitly using the sync fs methods)