Serving static files in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Express framework.

Node.js

const express = require('[1]');

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

Ahttp

Bexpress

Cfs

Dpath

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'http' instead of 'express' to import the framework.

Trying to import 'fs' or 'path' which are Node.js core modules but not Express.

The Express framework is imported using require('express').

2fill in blank

medium

Complete the code to serve static files from the 'public' folder.

Node.js

app.use(express.static('[1]'));

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

Apublic

Bstatic

Cassets

Dfiles

Attempts:

3 left

💡 Hint

Common Mistakes

Using a folder name that does not exist.

Forgetting to use express.static middleware.

The express.static middleware serves files from the folder named 'public'.

3fill in blank

hard

Fix the error in the code to correctly serve static files using Express.

Node.js

app.use([1].static('public'));

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

Apath

Bhttp

Cexpress

Dfs

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'http.static' or 'fs.static' which do not exist.

Forgetting to call the static method on the Express object.

The express.static middleware is used to serve static files, so express must be used here.

4fill in blank

hard

Fill both blanks to create an Express app that serves static files from 'assets' folder and listens on port 3000.

Node.js

const app = [1]();
app.use([2].static('assets'));

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

Aexpress

Bhttp

Dfs

Attempts:

3 left

💡 Hint

Common Mistakes

Using different modules for app creation and static serving.

Not calling express as a function to create the app.

You create an Express app by calling express() and use express.static to serve static files.

5fill in blank

hard

Fill all three blanks to complete the Express server that serves static files from 'static' folder and listens on port 8080.

Node.js

const app = [1]();
app.use([2].static('[3]'));
app.listen(8080);

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

Aexpress

Cstatic

Dhttp

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'http' instead of 'express' for app creation or static serving.

Incorrect folder name for static files.

The Express app is created by calling express(), static files are served from the 'static' folder using express.static, and the server listens on port 8080.

Practice

1. What is the main purpose of using express.static in a Node.js server?

easy

A. To manage user authentication

B. To handle database connections

C. To create dynamic HTML pages

D. To serve static files like images, CSS, and JavaScript to users

Solution

1. Step 1: Understand the role of express.static

   This middleware is designed to serve files such as images, CSS, and JavaScript directly to the browser.

2. Step 2: Compare with other server tasks

   Database connections, dynamic page creation, and authentication are handled by other parts of the server, not express.static.

3. Final Answer:

   To serve static files like images, CSS, and JavaScript to users -> Option D

4. Quick Check:

   Serving static files = A [OK]

Hint: Remember: static files are served by express.static middleware [OK]

Common Mistakes:

• Confusing static file serving with database handling
• Thinking express.static creates dynamic content
• Assuming express.static manages user login

2. Which of the following is the correct syntax to serve static files from a folder named public using Express?

easy

A. app.static('public')

B. app.use(express.static('public'))

C. express.use.static('public')

D. app.getStatic('public')

Solution

1. Step 1: Recall Express static middleware syntax

   The correct way is to call app.use(express.static('folderName')) to serve static files.

2. Step 2: Check each option

   Only app.use(express.static('public')) uses the correct method and syntax. Others are invalid or do not exist in Express.

3. Final Answer:

   app.use(express.static('public')) -> Option B

4. Quick Check:

   Correct static serving syntax = B [OK]

Hint: Use app.use with express.static and folder name [OK]

Common Mistakes:

• Using app.static instead of app.use(express.static)
• Calling express.use.static which is invalid
• Trying app.getStatic which does not exist

3. Given this Express code snippet:

const express = require('express');
const app = express();
app.use(express.static('assets'));
app.listen(3000);

What URL path would serve the file assets/logo.png?

medium

A. http://localhost:3000/assets/logo.png

B. http://localhost:3000/public/logo.png

C. http://localhost:3000/logo.png

D. http://localhost:3000/static/logo.png

Solution

1. Step 1: Understand express.static path mapping

   When serving static files from folder 'assets', the files are accessible at the root URL path, so 'logo.png' is at '/logo.png'.

2. Step 2: Analyze each URL option

   http://localhost:3000/logo.png matches the correct URL path. Options A, B, and C incorrectly add folder names to the URL path.

3. Final Answer:

   http://localhost:3000/logo.png -> Option C

4. Quick Check:

   Static folder files appear at root URL path = D [OK]

Hint: Static folder files appear at root URL unless a prefix is set [OK]

Common Mistakes:

• Adding folder name to URL path incorrectly
• Assuming static files need /static or /public prefix
• Confusing folder name with URL path

4. Identify the error in this code snippet that tries to serve static files from the static folder:

const express = require('express');
const app = express();
app.use(express.static.static('static'));
app.listen(3000);

medium

A. Incorrect use of express.static.static instead of express.static

B. Missing app.listen call

C. Folder name should be absolute path

D. Static files folder must be named 'public'

Solution

1. Step 1: Check the express.static usage

   The code incorrectly calls express.static.static. The correct call is express.static.

2. Step 2: Verify other parts

   App.listen is present, folder name can be relative, and folder name does not have to be 'public'.

3. Final Answer:

   Incorrect use of express.static.static instead of express.static -> Option A

4. Quick Check:

   Use express.static, not express.static.static [OK]

Hint: Use express.static, not express.static.static [OK]

Common Mistakes:

• Adding extra .static after express.static
• Thinking folder must be named 'public'
• Believing folder path must be absolute

5. You want to serve static files from the public folder but under the URL path prefix /static. Which code correctly achieves this?

hard

A. app.use('/static', express.static('public'))

B. app.use(express.static('/static/public'))

C. app.use('/public', express.static('static'))

D. app.get('/static', express.static('public'))

Solution

1. Step 1: Understand URL prefix with express.static

   To serve static files under a URL prefix, pass the prefix as the first argument to app.use, then the static middleware.

2. Step 2: Evaluate each option

   app.use('/static', express.static('public')) correctly uses app.use('/static', express.static('public')). Others either misuse paths or methods.

3. Final Answer:

   app.use('/static', express.static('public')) -> Option A

4. Quick Check:

   URL prefix with app.use('/prefix', express.static(folder)) = A [OK]

Hint: Use app.use('/prefix', express.static('folder')) for URL prefix [OK]

Common Mistakes:

• Putting URL prefix inside express.static argument
• Using app.get instead of app.use for static files
• Mixing folder and URL prefix names