Express

Question 1

What is a client?

Answer 1

program or device that sends requests

Question 2

what is a server?

Answer 2

program or device that receives requests from clients and sends back a response

Question 3

HTTP method when. you visit a url

Answer 3

GET

Question 4

first line of an HTTP request message?

Answer 4

The method protocol, target and version

Question 5

first line of an HTTP response message?

Answer 5

protocol, version status code and status message

Question 6

HTTP headers

Answer 6

metadata

Question 7

is the body required for a valid HTTP message?

Answer 7

nope

Question 8

what is NPM

Answer 8

NPM is the package manager for the Node JavaScript platform. It puts modules in place so that node can find them, and manages dependency conflicts intelligently.

npm consists of three distinct components:
• the website
• the Command Line Interface (CLI)
• the registry

Question 9

What is a package in npm

Answer 9

files of. code and it includes a package.json

Question 10

create a package.json with npm

Answer 10

npm init –yes

Question 11

What is a dependency and how to you add one to a package?

Answer 11

something that your code depends on. You add by npm install

Question 12

what happens when you install a dependency with npm?

Answer 12

adds another module in your directory and is assigned to the json file as a dependency

Question 13

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

Answer 13

app.listen(path, [callback])

Question 14

how to you mount a middleware with an Express application?

Answer 14

the use method

Question 15

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

Answer 15

request and response objects

Question 16

What is the appropriate content type header for HTTP messages that contain JSON in their bodies?

Answer 16

application/json

Question 17

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

Answer 17

if an incoming requisition message is application/json and the body is a string, it will parse the string

its needed for incoming request messages to parse bodies that are JSON

Question 18

what is the significance of an HTTP request message?

Answer 18

you can change and update data in your code and for communication purposes. it expresses what the client wants to do and the server responds accordingly

Question 19

What does express.static() return?

Answer 19

a function

Question 20

what is the local __dirname variable in a Node.js module?

Answer 20

the absolute path to the current directory.

Question 21

what does the join() method of Nodes path module do?

Answer 21

it joins strings to create a file path, putting slashes between them.