Question

I’m adding several numbers that were entered by a user and adding them to array list.

My code so far:

package project143;

import java.util.*;

/**
 * @author --
 */
public class Histogram {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        // Input for grades
        int mark = 0;
        List<Integer> list = new ArrayList<Integer>();
        while (mark >= 0 && mark <= 100) {
            System.out.println("Enter students mark:");
            mark = input.nextInt();

            if (mark >= 0 && mark <= 100) {
                list.add(mark);
            }

        }
        System.out.println(list);
    }
}

Now, I need to count how many numbers from the list are within following ranges (0-29 , 30-39 , 40-69 , 70-100)

Once I know how many numbers there are within each range, I need to display “” next to each range, so for example there are 10 numbers within range of 0 – 29, therefore I need to display 10 stars (***).

How can I achieve this?

Answer 1

You can do it this way without a list by putting this code in the loop you get input from…

 if (mark <= 29) ++bombout;
 else if (mark <= 39) ++fail;
 else if (mark <= 69) ++pass;
 else ++excellent;

…or if you want to use a List, iterate over it and put the code above in the loop.