express

Question 1

How do you add express to your package dependencies?

Answer 1

npm install express

Question 2

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

Answer 2

app.listen( )

Question 3

How do you mount a middleware with an Express application?

Answer 3

app.use( )

Question 4

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

Answer 4

req, res, next

mainly req and res

Question 5

What is the appropriate Content-Type header for HTTP messages that contain JSON in their bodies?

Answer 5

application/json

Question 6

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

Answer 6

• express.json returns middleware that only parses JSON and only looks at requests where the content-type header matches the ‘type’ option
• need it when you need to parse incoming JSON requests

Question 7

What is the significance of an HTTP request’s method?

Answer 7

• describes what we are trying to do (a way for us to express our intent)
• GET, PUT, POST, DELETE, etc..

Question 8

What does express.static( ) return?

Answer 8

• returns a middleware function, you tell it from which directory to serve files from and it does that

Question 9

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

Answer 9

• an absolute path to the directory containing the current module

Question 10

What does the join( ) method of Node’s path module do?

Answer 10

• path.join( ) joins all given path segments together using the platform-specific separator as a delimiter, then normalizes the resulting path