Node

Question 1

What are the 3 components of a fullstack Web architecture?

Answer 1

Front-end server, application server, back-end server.

Question 2

What is Node.js?

Answer 2

Node.js is a back-end JavaScript runtime environment

Question 3

What can Node.js be used for?

Answer 3

back-end

Question 4

What is a REPL?

Answer 4

Read-Eval-Print-Loop (REPL) is an easy-to-use command-line tool, used for processing Node. js expressions

Question 5

When was Node.js created?

Answer 5

May 27, 2009

Question 6

What backend languages have you heard of?

Answer 6

Python, PHP, Ruby, Java, C++

Question 7

What is a computer process?

Answer 7

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

Question 8

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

Answer 8

100+

Question 9

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

Question 10

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

Answer 10

The process object is 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 11

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

Answer 11

console.log(process)

Question 12

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

Answer 12

an Array of strings

Question 13

How do you access the command line arguments in a Node.js program?

Question 14

What is a JavaScript module?

Question 15

What are the advantages of modular programming?

Question 16

In JavaScript, how do you make a function in a module available to other modules?

Answer 16

export keyword

Question 17

In JavaScript, how do you use a function from another module?

Answer 17

import keyword.

Question 18

What is the JavaScript Event Loop?

Question 19

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

Answer 19

Blocking refers to operations that block further execution until that operation finishes while non-blocking refers to code that doesn’t block execution. Or as Node. js docs puts it, blocking is when the execution of additional JavaScript in the Node. js process must wait until a non-JavaScript operation completes.

Question 20

What is a directory?

Answer 20

a folder/container that holds files.

Question 21

What is a relative file path?

Answer 21

a file in the same directory

Question 22

What is an absolute file path?

Answer 22

always starts at the root of the file path.

Question 23

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

Answer 23

fs-module

Question 24

What method is available in the node:fs module for reading data from a file?

Answer 24

readFile(FILEPATH, OPTION)

Question 25

What method is available in the node:fs module for writing data to a file?

Answer 25

writeFile(fileneame, data)

Question 26

Are file operations using the fs module synchronous or asynchronous?

Answer 26

asynchronous because file operations are slow. So they are asynchronous to avoid blocking.

Question 27

What is NPM?

Answer 27

Node Package Manager.

Question 28

What is a package?

Answer 28

A directory with one or more files that usually have bit of code inside.

Question 29

How can you create a package.json with npm?

Answer 29

npm init –yes

Question 30

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

Answer 30

its a package that you depend on. npm install package-name

Question 31

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

Answer 31

Adds package name into dependencies field into package.json and creates a node_modules directory where the package is put and its dependencies.

Question 32

What are some other popular package managers?

Answer 32

Yarn, PNPM,

Question 33

What is Express useful for?

Answer 33

Useful for implementing routes or endpoints.

Question 34

How does Express fit into a full-stack web application?

Answer 34

On server side, manages the http requests.

Question 35

How do you add express to your package dependencies?

Answer 35

npm install express

Question 36

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

Answer 36

the listen() method
a port is an endpoint of a communication in an operating system. Specific port numbers are often used to identify specific services.

Question 37

What is Express middleware?

Answer 37

a function that takes in a request, does something, then calls next or response.

Question 38

What is Express middleware useful for?

Answer 38

changing http requests and then returning a response???

Question 39

How do you mount a middleware with an Express application?

Answer 39

Pass the middleware function through app.use

Question 40

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

Answer 40

the request, the response, and the next function

Question 41

What is an API endpoint?

Answer 41

a URL with API at the end.
the endpoint is the end of the URL.

Question 42

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

Answer 42

application/json

Question 43

What is the purpose of the Express Static middleware?

Answer 43

To serve static files such as images, CSS files, and JavaScript files, use the express.static built-in middleware function in Express. Express static sets up middleware that checks to see if a file exists and then calls sendFile on it.

Question 44

What does express.static() return?

Answer 44

a middleware function.

Question 45

What are several examples of static files?

Answer 45

Any kind of file can be served as static content as long as it does not change in response to a user’s actions or inputs. This includes images, JavaScript files, CSS files, videos, Flash files, even web pages.

Question 46

What is a good way to serve application images using Express?

Answer 46

use the express.static built-in middleware function