/*
Marty Stepp, CSE 142, Autumn 2009
This program prompts the user for numbers until 0
is typed, then displays the sum of the numbers.

This second version of the program uses a 'break' statement to exit
immediately out of a while loop to solve the fencepost problem.

Example output:
Enter a number (-1 to quit): 10
Enter a number (-1 to quit): 30
Enter a number (-1 to quit): 20
Enter a number (-1 to quit): 0
The sum is 60
*/

import java.util.*;   // for Scanner

public class SentinelSumBreak {
    public static final int SENTINEL = -1;

    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);

        // move one "post" out
        int sum = 0;
        while (true) {
            System.out.print("Enter a number (" + SENTINEL + " to quit): ");
            int n = console.nextInt();
            if (n == SENTINEL) {
                break;   // evil?
            }
            sum += n;   // sum = sum + n;   sum *= n;  sum = sum * n;
        }
        
        System.out.println("The sum is " + sum);
    }
}