Thread: Making Coin Toss for Football game

Hello, I am trying to construct a football simulator game, here is the code that I have so far:

import java.util.Scanner;
import java.util.Random;
 
public class gamePlay{
 
	public static int Downs = 0;
	public static int Yards = 0;
	public static String Coin = null;
	public static String Choice = null;
	public static String Toss = null;
	public static String heads;
	public static String tails;
	public static String Heads;
	public static String Tails;
	public static String Yes;
	public static String No;
public static void main (String[]args){
 
	Scanner keyboard = new Scanner(System.in);
 
	System.out.println("Welcome to todays game, it's time for the coin toss.");
	System.out.println("Please Pick Heads Or Tails By typing you answer.");
	String HT = keyboard.nextLine();
	switch(HT)
	{
	case "Heads":
	case "heads":
		Choice = heads;
		//TODO Make Answer Random
		coinToss();
		break;
	case "Tails":
	case "tails":
		Choice = tails;
		//TODO Make Answer Random
		coinToss();
		break;
		}
		//TODO Test The Above
 
	if(Coin == Heads && (Choice == heads))
	{
		System.out.println("You have won the coin toss!");
		Toss = Yes;
 
	}else if (Coin == Heads && (Choice == tails)){
		System.out.println("You have lost the coin toss...");
		Toss = No;
	}
	if(Coin == Tails && (Choice == tails))
	{	
		System.out.println("You have won the coin toss!");
		Toss = Yes;
	}else if (Coin == Tails && (Choice == heads)){
		System.out.println("You have lost the coin toss...");
		Toss = No;
	}
	if(Toss == Yes)
	{
	//Insert Something here
	}else if(Toss == No)
	{
	//Insert Something here
	}
}
 
public static void coinToss()
{
Random coin = new Random();
int coinRand = coin.nextInt(2);
 
if (coinRand == 0)
{
	System.out.println("The Result was Heads....");
	Coin = Heads;
}else{
System.out.println("The Result was Tails....");
Coin = Tails;
}
 
 
 
	}
 
}

My issue is when I run it, it prints "You have won the coin toss!" twice, no matter what the outcome is, could you explain to me what I am doing wrong?

This is a shot in the dark, but I would have used the toss = Math.random(). Then if between 0 and .5 would be equal to heads or tails. Then .6 to 1.0 will be
equal to the other.

I would then have a variable call.

if(call == toss)
{
   System.out.println("you won the toss");
}
 
else
{
   System.out.println("You lost the toss");
}

you are printing that out twice because any expression that evaluates to false will print that line, and in both those cases it does.

Ok, how would I make it only have 1 false and 1 true statement? Would it just be a single if-else statement instead?

I would try something like this:

 
public static String CoinToss(String toss)
{
   double call;
   double toss2;
   toss2 = Double.parseDouble(toss);
   String output;
 
  call = Math.random();
 
   if(call == toss)
   {
       output = "You won the coin toss";
    }
 
   else
    {
       output = "You lost the coin toss";
     }
   return output;
}

it should be (call == toss2) sorry

Your message prints twice because you have (as you frame it) 4 separate outcomes (choose heads / coin heads, choose heads / coin tails, choose tails / coin heads, choose tails / coin tails), and you have *two* if-else statements like

if (1)
{}
else if (2)
{}
if (3)
{}
else if (4)
{}

where you should have

if (1)
else if (2)
else if (3)
else if (4)

so that only one condition matches.
That would stop your message appearing twice, but there's another fault in your code: you're assigning

		Choice = heads;

but 'heads' is a String reference that has never been assigned - it is null, as is 'tails'