Question

I have two programs:

Score.java set to do the following:

• read scores from the keyboard and print their average.
• The scores will be numeric and may include a decimal part.

For example a score might be 8.73 or some such. Different contests will have different numbers of judges. It will keep asking for and reading in scores until the user types ‘done’. The program will then print the total score, the number of scores and the average score. The program will then prompt the user to see if there are any more contestants. If there are begin prompting for scores again. If there are no more then exit the program.” I have it set to stop the program when you enter “N”, and set to add future entries to the calculation after entering “Y”.

import java.util.Scanner;

// This is the Score program
// Written by me

public class Score
{
    public static void main(String args[])
    {
        Scanner game = new Scanner(System.in);
        double num = 0.0;
        double sum = 0.0;
        int cnt = 0;

        while (true)
        {
            System.out.println("Enter as many non-negative integers as you like ");
            System.out.println("one at a time and I will find the average");
            System.out.println("Enter done to stop entering numbers");

            System.out.print("enter number: ");
            String ans = game.next();
            while (!ans.equals("done"))
            {
                num = Double.parseDouble(ans);
                sum = sum + num;
                cnt = cnt + 1;

                System.out.print("enter number: ");
                ans = game.next();
            }
            System.out.println(cnt);
            System.out.println(sum);

            System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);

            System.out.println("Enter another contestant (Y/N)?");
            String str = game.next();
            if (!str.equals("Y"))
                break;
        }
    }
}

While the above process works, I cannot get my second program, Olympic.java, to work properly after typing “Y” to add more scores. Instead, it starts a whole new calculation of average instead of adding to the previous calculations:

import java.util.Scanner;

// This is the Olympic program
// Written by me

public class Olympic
{
    public static void main(String args[])
    {
        Scanner game = new Scanner(System.in);
        double num = 0.0;
        double sum = 0.0;
        int cnt = 0;
        double highscore = Double.MAX_VALUE;
        double lowscore = Double.MIN_VALUE;

        while (true)
        {
            System.out.println("Enter as many non-negative integers as you like ");
            System.out.println("one at a time and I will find the average");
            System.out.println("Enter done to stop entering numbers");

            System.out.print("enter number: ");
            String ans = game.next();
            lowscore = game.nextDouble();
            highscore = game.nextDouble();
            while (!ans.equals("done"))
            {
                num = Double.parseDouble(ans);
                sum = (sum + num) - lowscore - highscore;
                cnt = cnt + 1;

                System.out.print("enter number: ");
                if (num > highscore)
                {
                    highscore = num;
                }
                if (num < lowscore)
                {
                    lowscore = num;
                }
                ans = game.next();
            }
            System.out.println("Throwing out low score " + lowscore + " and high score " + highscore);
            System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);

            System.out.println("Enter another contestant (Y/N)?");
            String str = game.next();
            if (!str.equals("Y"))
                break;
        }
    }
}

Answer 1

So I did a really quick test

public static void main(String[] args) {

    Scanner game = new Scanner(System.in);

    while (true) {

        System.out.println("Enter another contestant (Y/N)?");
        String str = game.next();
        if (!str.equalsIgnoreCase("Y")) {
            break;
        }
    }

    System.out.println("I'm free");

}

And this will exit fine.

As to your second problem. I think your logic is a little skewed. You could try something like…

Scanner game = new Scanner(System.in);

double num = 0;
double sum = 0;
int cnt = 0;

while (true) {
    System.out.println("Enter as many non-negative integers as you like ");
    System.out.println("one at a time and I will find the average");
    System.out.println("Enter done to stop entering numbers");

    double lowscore = Double.MAX_VALUE;
    double highscore = 0;

    System.out.print("enter number: ");
    String ans = game.next();
    while (!ans.equals("done")) {

        num = Double.parseDouble(ans);

        lowscore = Math.min(lowscore, num);
        highscore = Math.max(highscore, num);

        sum += num;
        cnt++;

        System.out.print("enter number: ");
        if (num > highscore) {
            highscore = num;
        }
        if (num < lowscore) {
            lowscore = num;
        }
        ans = game.next();
    }

    sum -= lowscore;
    sum -= highscore;

    System.out.println("Throwing out low score " + lowscore + " and high score " + highscore);
    System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);

    System.out.println("Enter another contestant (Y/N)?");
    String str = game.next();
    if (!str.equalsIgnoreCase("Y")) {
        break;
    }
}

This will output…

Enter as many non-negative integers as you like 
one at a time and I will find the average
Enter done to stop entering numbers
enter number: 1
enter number: 2
enter number: 3
enter number: 4
enter number: 5
enter number: 6
enter number: 7
enter number: 8
enter number: 9
enter number: 10
enter number: done
Throwing out low score 1.0 and high score 10.0
Total Score 44.0 count scores 10 avg score 4.4
Enter another contestant (Y/N)?
y
Enter as many non-negative integers as you like 
one at a time and I will find the average
Enter done to stop entering numbers
enter number: 1
enter number: 12
enter number: 13
enter number: 14
enter number: 15
enter number: 16
enter number: 17
enter number: 18
enter number: 19
enter number: 20
enter number: done
Throwing out low score 1.0 and high score 20.0
Total Score 168.0 count scores 20 avg score 8.4
Enter another contestant (Y/N)?
n

As to your exception. When using Scanner.nextDouble, it will throw an exception if the input is not parsable as a double. You will need to deal with this situation as you see fit…