input: Write a python function to detect duplicate objects in an array.
  assert detectDuplicates([1, 2, 3, 4, 5])==False
  assert detectDuplicates([1, 2, 3, 2, 5])==True
  assert detectDuplicates(['a', 'b', 'c', 'd', 'a'])==True
output: def detectDuplicates(arr):
      seen = set()
      for item in arr:
          if item in seen:
              return True
          seen.add(item)
      return False