Express

Question 1

How do you add express to your package dependencies?

Answer 1

With ‘npm install express’.

Question 2

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

Answer 2

The ‘listen’ method.

Question 3

How do you mount a middleware with an Express application?

Answer 3

With the ‘use’ method.

Question 4

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

Answer 4

The request object (req) and the response (res) object.

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 is the significance of an HTTP request’s method?

Answer 6

To specify (TO HUMANS) what kind of request you are making to the server. Purely semantic.

Question 7

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

Answer 7

Parses incoming requests with JSON payloads and populates the request body with it. You would need it to deserialize data so that you can access JSON objects.

Question 8

What does express.static() return?

Answer 8

A function.

Question 9

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

Answer 9

A string containing the directory name of the current module. This is the same as the path.dirname() of the __filename.

Question 10

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

Answer 10

Joins all given path segments together into one path (using the platform-specific separator as a delimiter, then normalizes the resulting path).