input: Write a function to print out an array backwards.
  def print_reverse_array(arr):
   for i in range(len(arr)-1, -1, -1): 
    print(arr[i])
  
  assert print_reverse_array([1, 2, 3, 4, 5]) == None
  # Expected output: 5 4 3 2 1
  assert print_reverse_array(["a", "b", "c"]) == None
  # Expected output: c b a
  assert print_reverse_array([]) == None
  # Expected output: (No output)
output: def print_reverse_array(arr):
   for i in range(len(arr)-1, -1, -1): 
    print(arr[i])