input: Write a function to swap the elements of two arrays. The function should take two arrays of integers as input and swap their elements. If the lengths of the two arrays are not equal, the function should raise an assertion error.
  
  def swap(arr1, arr2):
      assert len(arr1) == len(arr2)
      for i in range(len(arr1)):
          temp = arr1[i]
          arr1[i] = arr2[i]
          arr2[i] = temp
  
  assert swap([3, 5, 6, 9], [2, 4, 7, 8]) == None
  assert swap([1, 2, 3], [4, 5, 6]) == None
  assert swap([10, 20], [30, 40]) == None
  assert swap([1], [2]) == None
output: def swap(arr1, arr2):
      assert len(arr1) == len(arr2)
      for i in range(len(arr1)):
          temp = arr1[i]
          arr1[i] = arr2[i]
          arr2[i] = temp