input: Write a function to calculate the sum of squares of all numbers in a given array of integers and return the result. If the array is empty, return 0.
  def sum_squares(arr):
      total = 0
      for num in arr:
          total += num ** 2
      return total
  
  assert sum_squares([2, 3, 4]) == 29
  assert sum_squares([1, 2, 3, 4]) == 30
  assert sum_squares([0, -1, 1]) == 2
  assert sum_squares([]) == 0
output: def sum_squares(arr):
      total = 0
      for num in arr:
          total += num ** 2
      return total