Dom Event Delegation

■ What this exercise teaches Listen for clicks on the element with id "list" and output the textContent of the clicked li with console.log.

Why it matters in real projects

Listening on the parent and checking e.target handles dynamically added children. Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "Dom Event Delegation" 2. Review the JavaScript (DOM) 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: addEventListener, target, LI. 6. After success, continue with adjacent exercises in the same category

Core concept explained

Listening on the parent and checking e.target handles dynamically added children.

Technical focus

Key JavaScript APIs: document.getElementById, console.log, addEventListener.

Hint before you peek at the solution

Use e.target to get the clicked element; check tagName for li.

Sample solution walkthrough

JavaScript APIs used: document.getElementById, console.log, addEventListener. Verify spelling and async/await usage. Explanation: Listening on the parent and checking e.target handles dynamically added children. Hint recap: Use e.target to get the clicked element; check tagName for li.

Solution code

Common mistakes for this exact task

- Skipping the hint: Use e.target to get the clicked element; check tagName for li. - getElementById returns null if the id string differs by even one character

Troubleshooting

Q: Preview does not change after Run A: Ensure you edited the JavaScript (DOM) pane and clicked Run. Q: Looks correct but check fails A: Auto-check looks for output containing: addEventListener, target, LI. 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 "Dom Event Delegation" in your own words within 30 seconds - Practice walking through each line of the sample solution on a whiteboard - Connect this task to a real component you would ship - Mention responsive or accessibility trade-offs - Describe when you use: document.getElementById, console.log, addEventListener

What to do after you pass

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

Keywords

Free hands-on exercise covering Event delegation, dom, intermediate, document.getElementById, console.log, addEventListener, dom event delegation—search-friendly guide for Dom Event Delegation.