input: Write a python function to sort an array of integers in ascending order.
  assert array_sort([5, 2, 9, 1, 5, 6]) == [1, 2, 5, 5, 6, 9]
  assert array_sort([3, 0, -2, 5, 12]) == [-2, 0, 3, 5, 12]
  assert array_sort([8, 7, 2, 3, 1]) == [1, 2, 3, 7, 8]
output: def array_sort(arr):
      return sorted(arr)