public class BadArraySum {
  public static void main(String[] args) {
    int[] numbers = {5, 14, 3, -8, 0, 194, 2};
    System.out.println("iterative sum : " + arraySumOne(numbers));
    // we didn't write a 1-argument method like the client asked!
    System.out.println("reverse sum : " + arraySumTwo(numbers));
  }

  public static int arraySumOne(int[] arr) {
    // an iterative approach to summing an array
    int sum = 0;
    for (int i = 0; i < arr.length; i++) {
      sum += arr[i];
    }
  }

  public static int arraySumTwo(int[] arr, int index) {
    if (arr.length == index) {
      return 0; // base case
    } else {
      // ...
      int first = arr[index];
      int sum = arraySumTwo(arr, index + 1);
      return first + sum;
    }
  }
}