Time: 0:00
Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).
This bug belongs to the off-by-one errors pattern
The loop that runs one time too many, the slice that drops the last item, the index that starts in the wrong place.
What went wrong: word.slice(0) is the whole word. The first letter is added once as a capital, then again with the rest.
The fix: return word.charAt(0).toUpperCase() + word.slice(1);
Remember: slice(1) means "everything from the second character".
The pattern behind it: off-by-one errors.
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<iframe src="https://trybughunt.com/embed/c7a034b8-44ba-4e81-a4cf-8b25372a94e8" title="Debugging challenge: Capitalize turns "debug" into "Ddebug"" width="100%" height="580" loading="lazy" style="border:1px solid #d4d4d8;border-radius:12px;max-width:760px"></iframe>
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