basic

Question 1

package that needs to be added to create a nodejs server

Answer 1

const http = require(‘http’);

Question 2

how do you create a node server once you have declare the correct package (module)

Answer 2

const server = http.createServer(requestListener)

Question 3

what is a requestListener?

Answer 3

a function that will be executed for each incoming request. You pass it as a parameter to method server.createServer()

Question 4

what is the structure of this requestListener?

Answer 4

a two parameter arrow function : (req, res) => { }

Question 5

how does the server work after you set the requestListener function?

Answer 5

it does nothing unless you run server.listen(). This listen method starts a process in which nodes listen to the requests on the port you specified. Example used is server.listen(3000) that will listen on port 3000

Question 6

what is the core definition of nodejs? what is it fundamentally. some equivalents in other platforms

Answer 6

a runtime. best homologo is aspnet. but any runtime framework (not only web) is

Question 7

from the terminal point of view what does nodejs keeps doing while it has listeners registered?

Answer 7

he keeps its event loop to listen for requests. this is the core of nodejs. when there’s no listeners registered then there’s no need to be runing and node ends. in terminal you see it the cursor back ready fr you to open word.

Question 8

main 3 properties of the req object

Answer 8

req.url, req.method, req.headers

Question 9

famous header that web pages all have? what is its value?

Answer 9

Content-Type that usually is “text/html”

Question 10

2 most used method in the response object

Answer 10

res.setHeader, res.write

Question 11

how do we tell the runtime (node) that we are done writing the response?

Answer 11

res.end();

Question 12

how do you return 200 or 302 or 500

Answer 12

res.statusCode = 302

Question 13

what 302 means

Answer 13

status code for redirection

Question 14

how do you write in a file

Answer 14

fs.writeTextSync(‘filename.txt’, “mnmnmn”);

Question 15

how do you redirect

Answer 15

res.setHeader(‘Location’, ‘/’); res.statusCode = 302

Question 16

how do you create the package.json

Answer 16

npm init and filling the information.

Question 17

what is the name of the field in the package json where you add the autorun configuration? y dentro de este? y then how you specify the app to run?

Answer 17

“scripts” y dentro de este “start”: “node app.js”

Question 18

how do you run your code from the autorun configuration?

Answer 18

npm start

Question 19

install nodemon in prod

Answer 19

npm install nodemon –save

Question 20

install nodemon in dev

Answer 20

npm install nodemon –save-dev

Question 21

install nodemon globally

Answer 21

npm install nodemon -g

Question 22

what is the name of folder created by nodejs when you add nodemon

Answer 22

node_modules

Question 23

when you install nodemon what is added to package. json? y si fuera installed solo para production?

Answer 23

“dev-dependencies”: {
“nodemod”: “^1.2.3”
}
“dependencies” : {

Question 24

how to make a modules update?

Answer 24

npm install

Question 25

what does package-lock.json do?

Answer 25

contains references to all the exact versions your project is using. When you publish your project then they can use this to run it against these package and not the latest versions

Question 26

convenience of deleting the node_package folder. who can readd it again and why?

Answer 26

if you finish working with a package you delete the node_module folder to save space, then since it is declared in the package.json file just running npm install it would get the latest versions again.

Question 27

what are core nodejs modules ?

Answer 27

you don't have to install them. just require them. Examples would be the file-system module ("fs"), the path module ("path") or the Http module ("http")

Question 28

what are third party modules?

Answer 28

You need to install them, and require them. nstalled via npm install - you can add any kind of feature to your app via this way Example nodemon

Question 29

what is a global feature?

Answer 29

features like const or function.

Question 30

what do you need to change in package.json to allow nodemon work?

Answer 30

not "start": "node app.js" anymore, but "start": "nodemon app.js"

Question 31

why you don't need to share your modules when you share your application?

Answer 31

because the other developer can run npm install and this will take from package.json and reinstall the latest versions. That way, you don't need to share node_modules folder.

Question 32

what are block variables in the debugger?

Answer 32

variables in the caller of the function that is being evaluated. they are blocked waiting

Question 33

what is the advantage of adding a variable to the watch section in debugger

Answer 33

you can see it while also can close local or other sections

Question 34

how do you add a configuration file for debugging? what is its name? under what folder is created? what fields need to be added?

Answer 34

debug/Add Configuration. se llama launch.json. .vscode folder. "restart":true; "runtimeExecutable": "nodemon" and "console": "integratedTerminal"

Question 35

does the debugger configured to re-start, and with nodemon find the package in the local node_modules?

Answer 35

no, you need to install it globally

Question 36

how do you export a function in nodejs?

Answer 36

module.exports = functionName

Question 37

ES6 way to declare a function in Javascript?

Answer 37

const functA = (req, res) => {};

Question 38

conventional folder name for your htmls? and for your routes files?

Answer 38

views and routes

Question 39

turn arrow function (req, res) => {} into an anonymous function

Answer 39

function(req, res) {}