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warmup8 min

Contains Duplicate

Contains Duplicate

Given an integer array nums, return true if any value appears at least twice, and false if every element is distinct. The clean answer uses a Set in one pass.

containsDuplicate([1, 2, 3, 1]); // true
containsDuplicate([1, 2, 3, 4]); // false

Run your code to see results.

Stuck? This challenge exercises:

javascript.data-structures