input: Write a function to swap the elements of two arrays of integers. The function should take two arrays as input and exchange their elements pairwise. If the lengths of the two arrays are not equal, the function should raise an AssertionError.
  assert swap([3, 5, 6, 9], [2, 4, 7, 8])==None
  assert swap([1, 2, 3], [4, 5, 6])==None
  assert swap([1], [2])==None
  assert swap([1, 2], [3, 4])==None
output: def swap(arr1, arr2):
      assert len(arr1) == len(arr2), "Arrays must be of equal length"
      for i in range(len(arr1)):
          arr1[i], arr2[i] = arr2[i], arr1[i]