input: Write a function in Python that takes an array of integer values and reverses the order of the values. The function should return the reversed array. If the input array is empty, the function should return an empty array.
  assert reverse_array([1, 2, 3, 4, 5])==[5, 4, 3, 2, 1]
  assert reverse_array([])==[] 
output: def reverse_array(arr):
      return arr[::-1]