Node.js

Question 1

What is Node.js?

Answer 1

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

Question 2

What can Node.js be used for?

Answer 2

To build back ends for web applications, command-line programs or any kind of automations that devs wish to perform.

Question 3

What is a REPL?

Answer 3

Read-eval-print loop. It is a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user.

Question 4

When was Node.js created?

Answer 4

It was created May 27, 2009

Question 5

What back end languages have you heard of?

Answer 5

JavaScript, Java, Python, Ruby, PHP, VBA

Question 6

What is a computer process?

Answer 6

The instance of a computer program that is being executed by one or many threads (smallest sequence of programmed instructions). It contains the program code and its activity.

Question 7

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

Answer 7

6

Question 8

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

Answer 8

Based on multiple processes to make applications work. Programming server and database.

Question 9

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

Answer 9

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

Question 10

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

Answer 10

You can just call the ‘process’ object since it is a global variable or by using require(‘process’).

Question 11

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

Answer 11

An array of strings

Question 12

What is a JavaScript module?

Answer 12

It is a file

Question 13

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

Answer 13

File name, dir name, exports, module, require

Question 14

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

Answer 14

Process and console

Question 15

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

Answer 15

To be able to access it from another file

Question 16

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

Answer 16

Using ‘require’ function using the relative file path

Question 17

What is a directory?

Answer 17

A file containing the list of files and/or directories

Question 18

What is a relative file path?

Answer 18

Starts with “./” (sibling directory) or “../” (parent directory)

Question 19

What is an absolute file path?

Answer 19

The full file path from the 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 synchronous and asynchronous, depending on the method

Question 23

How do you add express to your package dependencies?

Answer 23

Install npm express

Question 24

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

Answer 24

.listen()

Question 25

How do you mount a middleware with an Express application?

Answer 25

‘Use’ method of the app object.

Question 26

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

Answer 26

Request and response

Question 27

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

Answer 27

application/json

Question 28

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

Answer 28

The express.json parses the incoming json string and attached the object to req.body

Question 29

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

Answer 29

Desired action to get from the resource. A server can do whatever it wants with the request.