Node.js

Question 1

What is Node.js?

Answer 1

Runs on V8 engine and allows JS to run outside of a web browswer

Question 2

What can Node.js be used for?

Answer 2

Access JS in the backend

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. (ex: browser console)

Question 4

When was Node.js created?

Answer 4

2009

Question 5

What back end languages have you heard of?

Answer 5

Scripting languages: PHP, Python, Ruby, Perl, Lua
Systems languages: C, C++, Rust, D, Zig
Byte code languages: Java, C#,

Question 6

What is a computer process?

Answer 6

Instance of a program being executed.

Question 7

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

Answer 7

100 or more

Question 8

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

Answer 8

So they understand how much memory and moving parts of running. It’s part of potentially solving problems and writing viable code.

Question 9

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

Answer 9

A model of the node.js object that is running.

Question 10

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

Answer 10

Its a global object that can be accessed inside any module without requiring it.

Question 11

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

Answer 11

Array of strings

Question 12

What is a JavaScript module?

Answer 12

Its a file (.js)

Question 13

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

Answer 13

exports, module, require, __filename, __dirname

Question 14

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

Answer 14

Process, console, url

Question 15

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

Answer 15

Defines dependencies on other modules and makes it available.

Question 16

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

Answer 16

Require function

Question 17

What is a directory?

Answer 17

Folder that contains files and directs users where to go. It is essentially a file that lists other files.

Question 18

What is a relative file path?

Answer 18

Points to another file within a file.

Question 19

What is an absolute file path?

Answer 19

Path that points to a full url outside of the current page. Starts from root directory.

Question 20

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

Answer 20

fs module

Question 21

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

Answer 21

fs.writefile

Question 22

Are file operations using the fs module synchronous or asynchronous?

Answer 22

Both

Question 23

What is NPM?

Answer 23

Open source package manager to share and use code:. Refers to one of three things: cli, registry, and website

Question 24

What is a package?

Answer 24

Directory with one or more files with a package.json file

Question 25

How can you create a package.json with npm?

Answer 25

npm init

Question 26

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

Answer 26

Other packages that your code depends on

npm-install

Question 27

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

Answer 27

Adds it to package.json file and adds a directory with code in it (ex: node_modules)

Question 28

How do you add express to your package dependencies?

Answer 28

npm install express

Question 29

What Express application method starts the server and binds it to a network PORT?

Answer 29

listen method

Question 30

How do you mount a middleware with an Express application?

Answer 30

use method

Question 31

Which objects does an Express application pass to your middleware to manage the request/response lifecycle of the server?

Answer 31

req, res

Question 32

What is the appropriate Content-Type header for HTTP messages that contain JSON in their bodies?

Answer 32

application/json

Content Type signifies what data type is in the body.

Question 33

What is the significance of an HTTP request’s method?

Answer 33

Defines specific action between client and server

Question 34

What does the express.json() middleware do and when would you need it?

Answer 34

Parses incoming requests to JSON. You would use when you have to handle a request with a body in JSON.

Question 35

What does express.static() return?

Answer 35

Returns a middleware function

Question 36

What is the local __dirname variable in a Node.js module?

Answer 36

Path to whatever directory you are in

Question 37

What does the join() method of Node’s path module do?

Answer 37

Join all path segments together into one path separated by “/”