java coin toss simulator problems

Question

hi i am doing a coin toss simulator for java that must be done a certain way. it must have a string for sideup to hold the string of "heads" or "tails" made by a no arg constructor, the toss method must be void and it must have a getsideup method, then we must run the coin toss 20 times and diplay the number of heads and tails... i can do it easy with none void methods and just returning the result, but getting around this void and getsideup is driving me nuts. this is what i have so far.

import java.util.Random;
public class coin {
    public static String sideUp;

    public static void toss() {
        Random rand = new Random();
        int sideup = rand.nextInt(2);
        if (sideup == 0) {
            sideUp = "heads";
        } else {
            sideUp = "tails";
        }
    }

    public static String getsideup() {
        System.out.println(sideUp);
        return sideUp;
    }

    public static void main(String[] args) {
        // coin coin = new coin();
        int hcount = 0;
        int tcount = 0;
        for (int i = 1; i <= 20; i++) {
            if (getsideup().equals("heads")) {
                hcount++;
            } else {
                tcount++;
            }
        }
        System.out.println("total heads = " + hcount + " total tails = " + tcount);
    }
}

im hoping someone can tell me what im doing wrong and put me in the right direction.

Answer 1

You're not calling toss() at the beginning of your loop. That's required to set a value to sideUp, and required to give sideUp to change every toss.

Answer 2

The simple fix is put toss in your for loop before the if statement but I see a lot that can be done here. First I would add a constructor for the Coin class and add hcount and tcount to the class variables and make heads and tails constants:

private String sideUp;
private int hcount;
private int tcount;
private static final String HEADS = "Heads";
private static final String Tails = "Tails";

Coin()
{
    this.sideUp = HEADS;
    this.hcount = 0;
    this.tcount = 0;
}

Then I would make a method to check the toss:

public  void checkToss()
{
    if (getsideup().equals(HEADS)) 
        hcount++;
    else
        tcount++;
}

Now add the toss() and checkCoin() method to the for loop before the if statement. It should look like this:

for (int i = 1; i <= 20; i++)
{
    coin.toss(); 
    coin.checkToss();
}

I would also make a getter for the heads count and tails count:

public int getHeadsCount()
{
    return this.hcount;
}

public int getTailsCount()
{
    return this.tcount;
}

Everything put together looks like this:

import java.util.Random;
public class Coin 
{
    private  String sideUp;
    private int hcount;
    private int tcount;
    private static final String HEADS = "Heads";
    private static final String TAILS = "Tails";

    Coin()
    {
        this.sideUp = HEADS;
        this.hcount = 0;
        this.tcount = 0;
    }

    public void toss()
    {
        Random rand = new Random();
        int sideup = rand.nextInt(2);
        if (sideup == 0) 
            sideUp = HEADS;
        else 
            sideUp = TAILS;    
    }

    public String getsideup()
    {
        System.out.println(sideUp);
        return sideUp;
    }

    public void checkToss()
    {
    if (getsideup().equals(HEADS)) 
        this.hcount++;
    else
        this.tcount++;
    }

    public int getHeadsCount()
    {
        return this.hcount;
    }

    public int getTailsCount()
    {
        return this.tcount;
    }

    public static void main(String[] args)
    {
        Coin coin = new Coin();
        for (int i = 1; i <= 20; i++) 
        {
            coin.toss();
            coin.checkToss();
        }
        System.out.println("Total Heads = " + coin.getHeadsCount() + " Total Tails = " + coin.getTailsCount());
    }
}

Answer 3

import java.util.Random;
public class coin
{
public static String sideUp;
public int hcount=0;
public int tcount=0;

public static void toss()
     {
        Random rand = new Random();
        int sideup = rand.nextInt(2);
        if (sideup == 0)
            {
                sideUp = "heads";
                hcount++;
            }
            else 
            {
                sideUp  = "tails";
                tcount++;
            } 
      }       

  public static void main(String[] args)
  {
    for(int i=0;i<20;i++)
    {toss();}
    System.out.println("total heads = " + hcount + " total tails = " + tcount);
   }
}

Answer 4

for(int i = 1; i <= 20; i++) 
    {
        toss();
      if (getsideup().equals("heads")) 
      {
        hcount++;
      } else 
      {
        tcount++;
      }
    }