Why Node.js for server-side JavaScript in Node.js - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the HTTP module in Node.js.

Node.js

const http = require([1]);

Drag options to blanks, or click blank then click option'

A"http"

B"fs"

C"path"

D"url"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a module name unrelated to HTTP like 'fs' or 'path'.

Forgetting to put quotes around the module name.

Node.js uses the require function to import built-in modules like http for creating servers.

2fill in blank

medium

Complete the code to create a simple server that listens on port 3000.

Node.js

http.createServer((req, res) => {
  res.end('Hello World');
}).[1](3000);

Drag options to blanks, or click blank then click option'

Aopen

Brun

Clisten

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like 'start' or 'run' which do not exist on the server object.

Confusing the method with something like 'open'.

The listen method tells the server to start listening on a specific port.

3fill in blank

hard

Fix the error in the code to correctly handle asynchronous file reading in Node.js.

Node.js

const fs = require('fs');
fs.readFile('file.txt', [1], (err, data) => {
  if (err) throw err;
  console.log(data.toString());
});

Drag options to blanks, or click blank then click option'

Autf8

Btrue

Cbuffer

Dsync

Attempts:

3 left

💡 Hint

Common Mistakes

Passing 'true' or 'sync' which are not valid encodings.

Omitting the encoding and trying to use toString() without it.

Passing 'utf8' as the encoding makes readFile return a string instead of a buffer.

4fill in blank

hard

Fill both blanks to create a simple Express server that responds with 'Hi!' on the root URL.

Node.js

const express = require('express');
const app = express();
app.[1]('/', (req, res) => {
  res.[2]('Hi!');
});
app.listen(3000);

Drag options to blanks, or click blank then click option'

Aget

Bpost

Csend

Dwrite

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'post' instead of 'get' for the root URL.

Using 'write' instead of 'send' to respond.

Use get to handle GET requests and send to send a response in Express.

5fill in blank

hard

Fill all three blanks to create a Node.js server that reads a file and sends its content as a response.

Node.js

const http = require('http');
const fs = require('fs');
http.createServer((req, res) => {
  fs.readFile([1], [2], (err, data) => {
    if (err) {
      res.statusCode = 500;
      res.end('Error');
      return;
    }
    res.setHeader('Content-Type', [3]);
    res.end(data);
  });
}).listen(8080);

Drag options to blanks, or click blank then click option'

A'index.html'

B'utf8'

C'text/html'

D'style.css'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a CSS file instead of an HTML file.

Omitting the encoding or using wrong encoding.

Setting wrong content type like 'text/css'.

The server reads 'index.html' as a UTF-8 text file and sets the content type to 'text/html' before sending the response.