Time: 0:00
Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).
This bug belongs to the mutation and copying bugs pattern
Assignment does not copy, a shallow copy still shares its contents, and mutating methods return None.
What went wrong: 0.1 and 0.2 cannot be stored exactly in binary, so their sum is a tiny bit off.
The fix: return Math.round((a + b) * 100) / 100;
Remember: for money, round to cents or work in whole cents. This happens in almost every language.
The pattern behind it: mutation and copying bugs.
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<iframe src="https://trybughunt.com/embed/97c7c073-7082-4511-98ca-6239202dd225" title="Debugging challenge: 0.1 + 0.2 gives 0.30000000000000004" width="100%" height="580" loading="lazy" style="border:1px solid #d4d4d8;border-radius:12px;max-width:760px"></iframe>
<p style="font-size:14px">Debugging challenge from <a href="https://trybughunt.com/challenges/97c7c073-7082-4511-98ca-6239202dd225">TryBugHunt</a></p>