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Updated: May 31, 2026

Data Attributes

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Conclusion

Data Attributes — free browser-based HTML practice

■ What this exercise teaches Add data-id="123" and data-name="test" to the div.

Why it matters in real projects

Data attributes store custom data that JavaScript can read. Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "Data Attributes" 2. Review the HTML editor pane and start from the starter code 3. Open hints if stuck; compare your diff with the sample solution 4. Click Run and inspect preview/console output 5. Auto-check looks for output containing: data-id, data-name. 6. After success, continue with adjacent exercises in the same category

Core concept explained

Data attributes store custom data that JavaScript can read.

Technical focus

Key HTML elements in this task: div.

Hint before you peek at the solution

Attributes starting with data- are for custom data.

Sample solution walkthrough

The solution uses HTML tags such as div. Check nesting and closing tags. Explanation: Data attributes store custom data that JavaScript can read. Hint recap: Attributes starting with data- are for custom data.

Solution code

📝 Sample code
<div data-id="123" data-name="test">element</div>

Common mistakes for this exact task

- Skipping the hint: Attributes starting with data- are for custom data.

Troubleshooting

Q: Preview does not change after Run A: Ensure you edited the HTML pane and clicked Run. Q: Looks correct but check fails A: Auto-check looks for output containing: data-id, data-name. Look for typos, full-width spaces, or unclosed tags. Q: Console shows errors A: Open DevTools Console and fix bracket/quote mismatches at the reported line. Q: Hard to type on mobile A: Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview / portfolio tips

- Explain the techniques in "Data Attributes" in your own words within 30 seconds - Practice walking through each line of the sample solution on a whiteboard - Be ready to discuss tags: div - Mention responsive or accessibility trade-offs - Prepare one alternative approach and why you chose this one

What to do after you pass

Move to the next exercise in the html-advanced track, then continue the learning roadmap at /en/learning/html-basic/.

Keywords

Free hands-on exercise covering Data attributes, html-advanced, intermediate, div, data attributes—search-friendly guide for Data Attributes.

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■ Exercise task

Add data-id="123" and data-name="test" to the div.

Hint if stuck

Attributes starting with data- are for custom data.

10pt

Data attributes

Add data-id="123" and data-name="test" to the div.

Click error to highlight line. ✕=error ⚠=warning ›=log.

Roadmap · All guides

Deep dive

"Data Attributes" is a intermediate-level HTML exercise. Add data-id="123" and data-name="test" to the div. Run it in-browser with automatic checking.

Data attributes store custom data that JavaScript can read. Similar patterns appear daily in code review and production UI work.

Pair this with the html-basic roadmap. Exercise #29 reinforces core html-advanced skills.

Step-by-step workflow

  1. Read the guide and understand the goal of "Data Attributes"
  2. Review the HTML editor pane and start from the starter code
  3. Open hints if stuck; compare your diff with the sample solution
  4. Click Run and inspect preview/console output
  5. Auto-check looks for output containing: data-id, data-name.
  6. After success, continue with adjacent exercises in the same category

How to read the sample solution

The solution uses HTML tags such as div. Check nesting and closing tags. Explanation: Data attributes store custom data that JavaScript can read. Hint recap: Attributes starting with data- are for custom data.

Real-world & career relevance

Forms power sign-up, contact, and checkout. Proper label/input pairing is required in WCAG accessibility audits.

Common mistakes

  • Skipping the hint: Attributes starting with data- are for custom data.
  • label for and input id mismatch
  • inputs without name inside form
  • checkbox without associated label

Troubleshooting

Preview does not change after Run
Ensure you edited the HTML pane and clicked Run.
Looks correct but check fails
Auto-check looks for output containing: data-id, data-name. Look for typos, full-width spaces, or unclosed tags.
Console shows errors
Open DevTools Console and fix bracket/quote mismatches at the reported line.
Hard to type on mobile
Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview & portfolio tips

  • Explain the techniques in "Data Attributes" in your own words within 30 seconds
  • Practice walking through each line of the sample solution on a whiteboard
  • Be ready to discuss tags: div
  • Mention responsive or accessibility trade-offs
  • Prepare one alternative approach and why you chose this one

Glossary

form
Container for user input submitted to a server.
label
Describes an input; pair with for/id.
checkbox
On/off selection control.

Keywords covered on this page

Free hands-on exercise covering Data attributes, html-advanced, intermediate, div, data attributes—search-friendly guide for Data Attributes.

Related dev tools

Learning roadmap

Learning roadmap →

Related exercises

Frequently asked questions

Is "Data attributes" free?

This exercise is free and runs entirely in your browser. No account or credit card required.

Difficulty and time?

"Data attributes" is level "intermediate". Read the guide first; beginners can usually finish within 30 minutes. Allow 5–15 minutes per exercise. Use hints, then the solution if stuck.

What after a correct answer?

After a correct answer, use "Next exercise". When you finish a category, continue on the <a href="/en/learning/html-basic/">learning roadmap</a>.

Works on mobile?

Works on mobile browsers, but typing code is easier on a desktop.

Where are other exercises?

All exercises: <a href="/en/learn/">/en/learn/</a> with category filters.

Key takeaway for "Data attributes"?

Data attributes store custom data that JavaScript can read. Hint: Attributes starting with data- are for custom data.

Where does HTML Advanced fit?

Forms power sign-up, contact, and checkout. Proper label/input pairing is required in WCAG accessibility audits.

Step-by-step for "Data Attributes"?

1. Read the guide and understand the goal of "Data Attributes"<br />2. Review the HTML editor pane and start from the starter code<br />3. Open hints if stuck; compare your diff with the sample solution<br />4. Click Run and inspect preview/console output<br />5. Auto-check looks for output containing: data-id, data-name.<br />6. After success, continue with adjacent exercises in the same category

How to read the sample solution?

The solution uses HTML tags such as div. Check nesting and closing tags.<br /><br />Explanation: Data attributes store custom data that JavaScript can read.<br /><br />Hint recap: Attributes starting with data- are for custom data.

Something is not working?

<strong>Preview does not change after Run</strong> → Ensure you edited the HTML pane and clicked Run.<br /><strong>Looks correct but check fails</strong> → Auto-check looks for output containing: data-id, data-name. Look for typos, full-width spaces, or unclosed tags.<br /><strong>Console shows errors</strong> → Open DevTools Console and fix bracket/quote mismatches at the reported line.<br /><strong>Hard to type on mobile</strong> → Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Career / interview angle?

Explain the techniques in "Data Attributes" in your own words within 30 seconds Practice walking through each line of the sample solution on a whiteboard Be ready to discuss tags: div Mention responsive or accessibility trade-offs Prepare one alternative approach and why you chose this one

Related dev tools?

<a href="/en/tools/html-escape/">HTML Escape</a>, <a href="/en/tools/regex/">Regex Tester</a>

Prerequisites?

Read the <a href="/en/learning/html-basic/">Learning roadmap</a> chapter first.

Can I change the starter code?

Yes—if it works. Understanding the starter first, then adding minimal diffs, speeds up learning.

What do the points mean?

10pt is a difficulty hint, not a score you must maximize.