Node

Question 1

What is Node.js?

Answer 1

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

Question 2

What can Node.js be used for?

Answer 2

To build scalable network applications

Question 3

When was Node.js created?

Answer 3

2009

Question 4

What back end languages have you heard of?

Answer 4

PHP, C+, C++, C#, Java, Ruby, Python, Perl

Question 5

What is a computer process?

Answer 5

The instance of a computer program that is being executed by one or many threads. Contains program code and it’s activity

Question 6

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

Answer 6

About 2,000 or more

Question 7

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

Answer 7

To make sure their program works!

Question 8

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

Answer 8

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

Question 9

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

Answer 9

It’s always available because it is a GLOBAL

Question 10

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

Answer 10

It returns an array containing the command line arguments passed when the Node.js process was launched

Question 11

What is a JavaScript module?

Answer 11

A single JavaScript file

Question 12

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

Answer 12

exports, require, module, __filename, __dirname

Question 13

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

Answer 13

setTimeOut, setInterval, console, global

Question 14

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

Answer 14

Specify what variables/functions you want to make available for other modules

export is an object, so you can export properties

Question 15

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

Answer 15

by calling the require() function

Question 16

What is the JavaScript Event Loop?

Answer 16

The Event Loop has one simple job — to monitor the Call Stack and the Callback Queue. If the Call Stack is empty, it will take the first event from the queue and will push it to the Call Stack, which effectively runs it. Such an iteration is called a tick in the Event Loop. Each event is just a function callback.

Question 17

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

Answer 17

Blocking methods execute synchronously and non-blocking methods execute asynchronously.

Blocking is when the execution of additional JavaScript in the Node.js process must wait until a non-JavaScript operation completes. This happens because the event loop is unable to continue running JavaScript while a blocking operation is occurring.

Question 18

What is a directory?

Answer 18

A directory is a logical grouping of files. Directories are called folders

In computing, a directory is a file system cataloging structure which contains references to other computer files, and possibly other directories. On many computers, directories are known as folders

Question 19

What is a relative file path?

Answer 19

A relative file path points to a file relative to the current page

Question 20

What is an absolute file path?

Answer 20

An absolute file path is the full URL to a file

Question 21

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

Answer 21

the fs module

Question 22

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

Answer 22

the writeFile() method

Question 23

Are file operations using the fs module synchronous or asynchronous?

Answer 23

Asynchronous