Express.js

Question 1

How do you add express to your package dependencies?

Answer 1

Use npm install express.

When you do this, package.json dependencies gets updated with express. node_modules gets created with express and express’ dependancies, and the dependancies for those dependancies…etc

Question 2

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

Answer 2

.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

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

Answer 6

It parses incoming requests with JSON.

If the server is going to receive requests with a JSON body - you would need the express.json( ) middleware to parse it.

Question 7

What does express.static( ) return?

Answer 7

Returns a function - that function returns the static files requested.

Question 8

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

Answer 8

A string containing the directory name of the current module

Question 9

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

Answer 9

The path.join( ) method joins all given path segments together, then normalizes the resulting path.