Node.js - Mosh

Question 1

A runtime enviroment for executing Javascript code

Answer 1

Node.js

Question 2

What do we use node.js for?

Answer 2

To build back-end services (APIs)

Question 3

Who uses Back-end services?

Answer 3

Web Apps and Mobile Apps

Question 4

In what year was Node.js Created?

Answer 4

2009

Question 5

fs.readFIle ( ), http.createServer ( )

What are fs and http?

Answer 5

Objects of the node enviroment

Question 6

What does it mean Blocking - Synchronus?

Answer 6

A single thread is assigned per client.

Question 7

Node is non-blocking / Asynchronus by default?

Answer 7

True

Question 8

What is the output of this code?

var message = "Hey";
console.log ( global.message );

Answer 8

undefined

Question 9

The variables in the app.js are accesible in the global scope. True or false

Answer 9

false

Question 10

What is considered a module?

Answer 10

A js file. Ex: app.js

Question 11

How can I use a code outside of a module?

Answer 11

I need to export it.

Question 12

What is the output of this code? <br></br>

console.log ( module );

Answer 12

it displays a json file

Question 13

What does this code do? <br>
function log ( ) {  code }
module.export.log = log

Answer 13

Exports the function log

Question 14

What is the function we use in node to load a module?

Answer 14

require ( )

Question 15

What is the Module Wrapper Function?

Answer 15

It’s a IIFE used to config the module.

Question 16

What are the variables that the Module Wrapper Function enables?

Answer 16

• exports
• require
• module
• __filename
• __dirname

Question 17

How do we use the node modules?

Answer 17

Using the require ( ) in our module.

Question 18

What are the core functionalities based on?

Answer 18

Events

Question 19

What does an Event indicate?

Answer 19

Indicates that something has happended in our app

Question 20

What is the convention for classes names?

Answer 20

the first letter is uppercase

Question 21

What does this code do?
const EventEmitter = require ( 'events' );
const emitter = new EventEmitter ( );

Answer 21

It loads the events node module.

And creates an instances of that class

Question 22

A class is like the person John and an object is like human.
True or False?

Answer 22

False. Opposite

Question 23

const EventEmitter = require ( 'events' );
const emitter = new EventEmitter ( );

Which is the object and which the class?

Answer 23

EventEmitter is the class.

emitter is the object.