Express

Question 1

How do you mount a middleware with an Express application?

Answer 1

app.use()

Question 2

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

Answer 2

A request object (req)
A response object (res)
A next object (next)

Question 3

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

Answer 3

application/json

Question 4

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

Answer 4

It’s used to parse incoming requests with a JSON body and assign the parsed data to req.body and one would need it when passing JSON objects to the server for some form of processing

Question 5

What does express.static() return?

Answer 5

It returns a middleware function that serves static files.

Question 6

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

Answer 6

It is a local variable that returns the directory name of the current module. It returns the folder path of the current JavaScript file.

Question 7

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

Answer 7

It joins together path segments together, normalizes them, and then returns the resulting path.