Getting a new random number every time [Dice Simulator]

Question

Hey guys I'm quite new to Java, and just started meddling with classes. I'm currently trying to simulate a dice on a basic game I'm creating. The dice seems to work, but I can only call it effectively once, as the number always remains the same after that. Is there an easy solution for the dice I've created to be difference every time I call it?

public class Dice {
  Random randomNum = new Random();

  public int diceRoll() {
    int diceResult = 0;
    int result = randomNum.nextInt(20) + 1;
    diceResult = diceResult + result;
    return diceResult;
  }
}

Appreciate any help in the slightest, thank you

Edit: Thank you for the feedback guys. It turned out my code was calling the original random value I used on an integer, as I didn't change its value to a new number everytime I was calling it.

Thanks again for helping me realize it wasn't the Dice class itself. Appreciate it! :)

Possible duplicate of [Generating Unique Random Numbers in Java](https://stackoverflow.com/questions/8115722/generating-unique-random-numbers-in-java) — Stefan, Nov 10 '17 at 09:58
the code you've shown will not _always_ generate the same number, that _might_ happen more often when a couple of numbers are generated than several and also partly due to the range given to `nextInt` — Ousmane D., Nov 10 '17 at 10:01
Cannot reproduce your problem. Every call of the diceRoll function works just as expected (returning a random number from 1 to 20) — OH GOD SPIDERS, Nov 10 '17 at 10:01
yes, what you are doing seems coirrect and should be generating random numbers. — akshaya pandey, Nov 10 '17 at 10:01

score 1 · Accepted Answer · answered Nov 10 '17 at 10:04

Tried your code, working fine.

import java.util.Random;
    public class Main {
        Random randomNum = new Random();
        public static void main(String[] args) throws Exception {
            Main main = new Main();
            for (int i =0; i<20; i++) {
                System.out.println(main.diceRoll());
            }
        }

        public int diceRoll()
        {
            int diceResult = 0;
            int result = randomNum.nextInt(20) + 1;
            diceResult = diceResult + result;
            return diceResult;
        }
    }

O/P

Can you please share your O/P

score 0 · Answer 2 · answered Nov 10 '17 at 10:37

Have you tried instantiating the Random object inside your method like so?

public class Dice {


  public int diceRoll() {
    Random randomNum = new Random();
    int diceResult = 0;
    int result = randomNum.nextInt(20) + 1;
    diceResult = diceResult + result;
    return diceResult;
  }
}

The Random class is pseudo random and it's seeded by the date at the point of instantiation. You'd certainly get better random values in C#. It's worth giving this a go.

score 0 · Answer 3 · answered Nov 10 '17 at 10:41

Thank you for the feedback guys. It turned out my code was calling the original random value I used on an integer, as I didn't change its value to a new number everytime I was calling it.

Thanks again for helping me realize it wasn't the Dice class itself. Appreciate it! :)

Getting a new random number every time [Dice Simulator]

3 Answers3