input: Write a python function to swap the elements of two arrays of the same length.
  assert swap([1, 2, 3], [4, 5, 6])==([4, 5, 6], [1, 2, 3])
  assert swap([7, 8, 9], [10, 11, 12])==([10, 11, 12], [7, 8, 9])
  assert swap([0, 0, 0], [1, 1, 1])==([1, 1, 1], [0, 0, 0])
output: def swap(arr1, arr2):
      if len(arr1) != len(arr2):
          raise ValueError("Arrays must be of the same length")
      return arr2, arr1