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

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

Question 3

What is a REPL?

Answer 3

Read-eval-print_loop; A simple development environment that takes single user inputs executes them, and returns the result to the user.

Question 4

When was Node.js created?

Answer 4

Node.js was created in 2009 by Ryan Dahl.

Question 5

What back end languages have you heard of?

Answer 5

PHP, Java, Ruby, and Python

Question 6

What is a computer process?

Answer 6

An instruction currently being carried out by the computer.

Question 7

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

Answer 7

100+

Question 8

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

Answer 8

So you can understand how the computer interprets instructions and make your programs more efficient.

Question 9

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

Answer 9

A global object 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

Since it’s a global object you can just reference it by name.

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

A JavaScript file.

Question 13

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

Answer 13

__filename, __dirname, require, exports, module

Question 14

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

Answer 14

console, process, setInterval, setTimeout, clearInterval, clearTimeout, global

Question 15

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

Answer 15

So that we can access files from elsewhere in the code (another module).

Question 16

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

Answer 16

With the require method.

Question 17

What is the JavaScript Event Loop?

Answer 17

The event loop checks if the stack is clear so it can push callbacks to the stack from the task queue.

Question 18

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

Answer 18

‘blocking’ code is on the stack, ‘non-blocking’ is on the queue.

Question 19

What is a directory?

Answer 19

A location for storing files.

Question 20

What is a relative file path?

Answer 20

A path to another file based off of the current location.

Question 21

What is an absolute file path?

Answer 21

A path to a file based off of the root directory.

Question 22

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

Answer 22

The fs module.

Question 23

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

Answer 23

fs.writeFile( file, data, callback)

Question 24

Are file operations using the fs module synchronous or asynchronous?

Answer 24

Asynchronous