input: Write a function in Python to print out an array backwards. If the input array is empty, simply print nothing.
  assert print_reverse_array([1, 2, 3]) is None
  assert print_reverse_array([5, 6, 7, 8]) is None
  assert print_reverse_array([]) is None
output: def print_reverse_array(arr):
      for i in range(len(arr)-1, -1, -1):
          print(arr[i])