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Thread: random problem

  1. #1
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    Default random problem

    import java.util.ArrayList;
     
    import org.riediger.jconsole.JConsole;
     
    public class Ships {
        private String name;
        private int[] location;
     
        public void setLocation(int[] array) {
            location = array;
        }
     
        public String[] createShip() {
            ArrayList<String> vertical = new ArrayList<String>();
            String[] array = { "A", "B", "C", "D", "E", "F" };
            for (String count : array) {
                vertical.add(count);
            }
     
            String[] cords = new String[2];
            cords[0] = vertical.get((int) Math.random() * vertical.size());
            cords[1] = "" + ((int) Math.random() * 6);
            return cords;
        }
     
        public static void main(String[] args) {
            JConsole.start();
            Ships one = new Ships();
            String[] array = new String[2];
            array = one.createShip();
            System.out.println(array[0]);
            System.out.println(array[1]);
     
        }
     
    }

    hello,
    this block of code gives me a strange result.
            cords[0] = vertical.get((int) Math.random() * vertical.size());
            cords[1] = "" + ((int) Math.random() * 6);
    I always get A0 as my output. What happend wrong ?
    the ouput should be B3,F2,A6 etc.


  2. #2
    Member
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    Default Re: random problem

    Problem with casting.

    (int) Math.random() * 6
    should be
    (int) (Math.random() * 6)

    Similar correction for the other one.
    What happened in your case was that random() which is between 0.0 and 1.0 got truncated to 0.

  3. #3
    Junior Member
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    Default Re: random problem

    arg... yes thanks =)

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