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Updated: 2026年5月31日
First Html
Original task (JA): 最初のHTML
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Conclusion
First Html — free browser-based HTML practice
Why it matters in real projects
HTMLの基本は開始タグと終了タグで要素を囲むことです。h1は最も大きな見出しを表します。 Similar patterns appear daily in code review and production UI work.Step-by-step workflow
1. Read the guide and understand the goal of "First Html" 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: Hello World, hello world, helo world. 6. After success, continue with adjacent exercises in the same categoryCore concept explained
HTMLの基本は開始タグと終了タグで要素を囲むことです。h1は最も大きな見出しを表します。Technical focus
Key HTML elements in this task: h1.Hint before you peek at the solution
h1タグを使います。<h1>と</h1>で囲みます。Sample solution walkthrough
The solution uses HTML tags such as h1. Check nesting and closing tags. Explanation: HTMLの基本は開始タグと終了タグで要素を囲むことです。h1は最も大きな見出しを表します。 Hint recap: h1タグを使います。<h1>と</h1>で囲みます。Solution code
📝 Sample code
<h1>Hello World</h1>Common mistakes for this exact task
・Skipping the hint: h1タグを使います。<h1>と</h1>で囲みます。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: Hello World, hello world, helo world. 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 "First Html" in your own words within 30 seconds ・Practice walking through each line of the sample solution on a whiteboard ・Be ready to discuss tags: h1 ・Mention responsive or accessibility trade-offs ・Prepare one alternative approach and why you chose this oneWhat to do after you pass
Move to the next exercise in the environment track, then continue the learning roadmap at /en/learning/environment/.Keywords
Free hands-on exercise covering 最初のHTML, environment, 入門, h1, first html—search-friendly guide for First Html.🧪 Try it here — safe to break things
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Jump to editor■ Exercise task
「Hello World」と表示するHTMLを書いてください。上で学んだh1タグを使います。
Hint if stuck
h1タグを使います。<h1>と</h1>で囲みます。