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Updated: 2026年5月31日

Checkbox

Original task (JA): チェックボックス

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Conclusion

Checkbox — free browser-based HTML practice

■ What this exercise teaches 「同意する」というラベル付きのチェックボックスを作ってください。

Why it matters in real projects

チェックボックスは複数選択可能な入力です。 Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "Checkbox" 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: checkbox, 同意する. 6. After success, continue with adjacent exercises in the same category

Core concept explained

チェックボックスは複数選択可能な入力です。

Technical focus

Key HTML elements in this task: label, input.

Hint before you peek at the solution

input type="checkbox"、labelで囲む

Sample solution walkthrough

The solution uses HTML tags such as label, input. Check nesting and closing tags. Explanation: チェックボックスは複数選択可能な入力です。 Hint recap: input type="checkbox"、labelで囲む

Solution code

📝 Sample code
<label><input type="checkbox" name="agree"> 同意する</label>

Common mistakes for this exact task

・Skipping the hint: input type="checkbox"、labelで囲む

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: checkbox, 同意する. 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 "Checkbox" in your own words within 30 seconds ・Practice walking through each line of the sample solution on a whiteboard ・Be ready to discuss tags: label, input ・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 チェックボックス, html-advanced, 初級, label, input, checkbox—search-friendly guide for Checkbox.

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■ Exercise task

「同意する」というラベル付きのチェックボックスを作ってください。

Hint if stuck

input type="checkbox"、labelで囲む

15pt

チェックボックス

同意するというラベル付きのチェックボックスを作ってください。

エラーをクリックで該当行をハイライト。✕=エラー ⚠=警告 ›=ログ。

Roadmap · All guides

Deep dive

"Checkbox" is a 初級-level HTML exercise. 「同意する」というラベル付きのチェックボックスを作ってください。 Run it in-browser with automatic checking.

チェックボックスは複数選択可能な入力です。 Similar patterns appear daily in code review and production UI work.

Pair this with the html-basic roadmap. Exercise #30 reinforces core html-advanced skills.

Step-by-step workflow

  1. Read the guide and understand the goal of "Checkbox"
  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: checkbox, 同意する.
  6. After success, continue with adjacent exercises in the same category

How to read the sample solution

The solution uses HTML tags such as label, input. Check nesting and closing tags. Explanation: チェックボックスは複数選択可能な入力です。 Hint recap: input type="checkbox"、labelで囲む

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: input type="checkbox"、labelで囲む
  • 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: checkbox, 同意する. 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 "Checkbox" in your own words within 30 seconds
  • Practice walking through each line of the sample solution on a whiteboard
  • Be ready to discuss tags: label, input
  • 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 チェックボックス, html-advanced, 初級, label, input, checkbox—search-friendly guide for Checkbox.

Related dev tools

Learning roadmap

Learning roadmap →

Related exercises

Frequently asked questions

Is "チェックボックス" free?

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

Difficulty and time?

"チェックボックス" is level "初級". 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 learning roadmap.

Works on mobile?

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

Where are other exercises?

All exercises: /en/learn/ with category filters.

Key takeaway for "チェックボックス"?

チェックボックスは複数選択可能な入力です。 Hint: input type="checkbox"、labelで囲む

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 "Checkbox"?

1. Read the guide and understand the goal of "Checkbox"
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: checkbox, 同意する.
6. After success, continue with adjacent exercises in the same category

How to read the sample solution?

The solution uses HTML tags such as label, input. Check nesting and closing tags.

Explanation: チェックボックスは複数選択可能な入力です。

Hint recap: input type="checkbox"、labelで囲む

Something is not working?

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: checkbox, 同意する. 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.

Career / interview angle?

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

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?

15pt is a difficulty hint, not a score you must maximize.