input: Write a python function to count the number of odd numbers in an array.
  assert countOddNumbers([2, 3, 5, 7]) == 3
  assert countOddNumbers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == 5
  assert countOddNumbers([10, 20, 30, 40, 50]) == 0
output: def countOddNumbers(arr):
      return sum(1 for num in arr if num % 2 != 0)