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

const express = require('express');
const app = express();
app.listen(3000, () => {
  // eslint-disable-next-line no-console
  console.log('Express server listening on port 3000');
});

listen method

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

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

enable communications between clients and servers

Question 7

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

Answer 7

parses incoming JSON requests and puts the parsed data in req

Question 8

What does express.static() return?

Answer 8

HTTP 404 if it can’t find a file, so that means you should typically call app.use(express. static()) after the rest of your app.

returns a function, and that functions returns file or the error message.

Question 9

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

Answer 9

an environment variable that tells you the absolute path of the directory containing the currently executing file

Question 10

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

Answer 10

joins the specified path segments into one path

joins multiple segments of the file path.