About this challenge
Fix Typo in Loop is a easy debugging coding challenge. It tests your ability to read unfamiliar code, find the defect, and fix it without breaking the rest. Write your solution in the editor above, run it against the test cases, and get instant feedback — free, in your browser, no sign-up.
Show a hint & approach (spoiler)
Hint: The starting index should be arr.length - 1, not arr.length. Then you do not need the `!== undefined` guard.
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