Thread: While Statements/Boolean Based Program Help

Hi, i'm new to coding with Java so keep that in mind. To practice I thought it would be a fun idea to create a super simple football simulator through the console that would just do a coin toss, then randomly decide if its going to be a Turnover (50%), and Field Goal (25%), or a Touch Down (25%). Then just to end it for now I made it so the game would stop when a team reaches 50 points or higher. Here is the code... (I use Eclipse IDE btw)

public class Simulator {
 
	public static void main(String[] args) {
		int touchDown = 7;
		int fieldGoal = 3;
		int homeScore = 0;
		int awayScore = 0;
		String total = "Home: " + homeScore + " Away: " + awayScore;
		boolean homeBall = false;
		boolean awayBall = false;
		double coinToss = Math.random();
 
		if (coinToss <= 0.5){
			homeBall = true;
			System.out.println("The home team won the coin toss!");
		}else{
			awayBall = true;
			System.out.println("The away team won the coin toss!");
		}
 
		if (homeScore >= 50){
			homeBall = false;
			awayBall = false;
			System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
		}
 
		if (awayScore >= 50){
			homeBall = false;
			awayBall = false;
			System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
		}
 
		if (homeBall = true){
			double homeChance = Math.random();
			if (homeChance < 0.5){
				homeBall = false;
				awayBall = true;
				System.out.println("Home turnover!");
			}
			if (0.5 <= homeChance){
				if (homeChance < 0.75){
					homeScore = homeScore + fieldGoal;
					System.out.println(total);
					homeBall = false;
					awayBall = true;
				}else{
					homeScore = homeScore + touchDown;
					System.out.println(total);
					homeBall = false;
					awayBall = true;
				}
			}
		}
 
		if (awayBall = true){
			double awayChance = Math.random();
			if (awayChance < 0.5){
				homeBall = true;
				awayBall = false;
				System.out.println("Away turnover!");
			}
			if (0.5 <= awayChance){
				if (awayChance < 0.75){
					awayScore = awayScore + fieldGoal;
					System.out.println(total);
					homeBall = true;
					awayBall = false;
				}else{
					awayScore = awayScore + touchDown;
					System.out.println(total);
					homeBall = true;
					awayBall = false;
				}
			}
		}
 
	}
 
}

The problem is that it always ends up stopping basically right after the first possession and its almost always a turnover too. I'm new to while/do statements so that might be related to the solution. I would appreciate anyone's help!

You mention being new to looping, and that's exactly what you need here. Right now your program runs from top to bottom or from start to finish without repeating any of the code between. Repeating code is done with some kind of loop. I recommend you read about controlling program flow.

Thanks for the reply Greg. I've been researching about loops and I still cant seem to find out what's wrong with my code. Do I need to put the last two big loops at the beginning of the program?

I've been researching about loops . . .

Then you probably know that the typical loops are for loops, while loops, and do/while loops.

. . . Do I need to put the last two big loops . . .

What "last two big loops?" I don't see a for, while, or do/while loop anywhere in your code.

Would you recommend a for loop? Because when I try a while loop it just goes insane forever.

While one type of loop might be more appropriate in a given situation than the others, ALL can be written to be interchangeable. Show what you tried and describe the results. Show the whole program in its runnable form, even though it goes insane forever (an infinite loop).

public class Simulator {
 
	public static void main(String[] args) {
		int touchDown = 7;
		int fieldGoal = 3;
		int homeScore = 0;
		int awayScore = 0;
		String total = "Home: " + homeScore + " Away: " + awayScore;
		boolean homeBall = true;
		boolean awayBall = false;
 
		while (homeBall = true){
			double homeChance = Math.random();
			if (homeChance < 0.5){
				homeBall = false;
				awayBall = true;
				System.out.println("Home turnover!");
			}
			else if (0.5 <= homeChance){
				if (homeChance < 0.75){
					homeScore = homeScore + fieldGoal;
					System.out.println(total);
					homeBall = false;
					awayBall = true;
				}else{
					homeScore = homeScore + touchDown;
					System.out.println(total);
					homeBall = false;
					awayBall = true;
				}
			}
		}
 
		while (awayBall = true){
			double awayChance = Math.random();
			if (awayChance < 0.5){
				homeBall = true;
				awayBall = false;
				System.out.println("Away turnover!");
			}
			else if (0.5 <= awayChance){
				if (awayChance < 0.75){
					awayScore = awayScore + fieldGoal;
					System.out.println(total);
					homeBall = true;
					awayBall = false;
				}else{
					awayScore = awayScore + touchDown;
					System.out.println(total);
					homeBall = true;
					awayBall = false;
				}
			}
		}
 
		double coinToss = Math.random();
		if (coinToss <= 0.5){
			homeBall = true;
			System.out.println("The home team won the coin toss!");
		}else{
			awayBall = true;
			System.out.println("The away team won the coin toss!");
		}
 
		if (homeScore >= 50){
			homeBall = false;
			awayBall = false;
			System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
		}
 
		if (awayScore >= 50){
			homeBall = false;
			awayBall = false;
			System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
		}
 
 
 
	}
 
}

I didn't change much except move the while homeBall and the while awayBall things up. Also changed the ifs to whiles. The output of the program is always super messed up and I have no clue how it end up like this: (with if)

Home: 0 Away: 0
Away turnover!
The home team won the coin toss!

OR this over and over forever: (with while)

Home turnover!
Home: 0 Away: 0
Home turnover!
Home: 0 Away: 0
Home: 0 Away: 0
Home: 0 Away: 0
Home: 0 Away: 0
Home turnover!
Home: 0 Away: 0
Home: 0 Away: 0
Home: 0 Away: 0
Home: 0 Away: 0
Home: 0 Away: 0
Home turnover!
Home turnover!
Home turnover!
Home turnover!
Home turnover!
Home: 0 Away: 0
Home turnover!
Home: 0 Away: 0
Home turnover!

If you could redo some of the code for me or something like that I would greatly appreciate it. I didn't think that this would turn out so messed up :/.

These statements can be improved on a couple levels:

while (homeBall = true)

'=' is the assignment operator, '==' is to compare equality. However, there's no reason to compare a boolean to true or false, simply use the boolean variable as the condition, as in:

while ( homeBall ).

Let me look at the rest of your code to see what else can be improved. Why don't you do the same.

After further study:

I think you have all of the necessary parts, but I suggest you reorder some of the parts and then wrap the parts that make up a game in another loop, something like:

Decide coin toss. (This part is currently at the end of play - ?)

Start Game Loop: while ( gameInProgress ):

homeBall or awayBall loops.

if either score >= 50, gameInProgress = false

End Game Loop.

Print final score.

Further, this statement is a great idea:

String total = "Home: " + homeScore + " Away: " + awayScore;

but, unfortunately, it doesn't update the way you'd like it to. The String total is set when homeScore and awayScore are both zero, and it won't change. Instead, you need a method, like:

private static String getScore()
{
    return "Home: " + homeScore + " Away: " + awayScore;
}

That approach will require you to move declaration of the variables homeScore and awayScore outside of the main() method, but we can help you with that, if you don't know how.

Move things around and add the loop as I suggested, and then we can work on printing the scores as each round ends.

Will do.

See what I added to my previous post.

Sounds good but for your information I haven't got to methods yet so for now i'm going to try and avoid them while I can just for learning and comprehension purposes. But everything else like the game in progress loop sounds efficient. I'll start messing around with that.

Then instead of a method, do this to print the score each time:

System.out.println( "Home: " + homeScore + " Away: " + awayScore );

instead of:

System.out.println(total);

public class Simulator {
 
	public static void main(String[] args) {
		int touchDown = 7;
		int fieldGoal = 3;
		int homeScore = 0;
		int awayScore = 0;
		String total = "Home: " + homeScore + " Away: " + awayScore;
		boolean homeBall = true;
		boolean awayBall = false;
		boolean gameInProgress = false;
 
		//Coin Toss
 
		double coinToss = Math.random();
		if (coinToss <= 0.5){
			homeBall = true;
			System.out.println("The home team won the coin toss!");
			gameInProgress = true;
		}else{
			awayBall = true;
			System.out.println("The away team won the coin toss!");
			gameInProgress = true;
		}
 
		//Game loop
 
		while (gameInProgress){
			//Test to end
			if (homeScore >= 50){
				gameInProgress = false;
				System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
			}
 
			if (awayScore >= 50){
				gameInProgress = false;
				System.out.println("Final Score: Home " + homeScore + ", Away " + awayScore);
			}
			//Game loop
			while (homeBall){
			double homeChance = Math.random();
			if (homeChance < 0.5){
				System.out.println("Home turnover!");
				System.out.println( "Home: " + homeScore + " Away: " + awayScore );
				homeBall = false;
				awayBall = true;
			}
			else if (0.5 <= homeChance){
				if (homeChance < 0.75){
					homeScore = homeScore + fieldGoal;
					System.out.println("Home field goal!");
					System.out.println( "Home: " + homeScore + " Away: " + awayScore );
					homeBall = false;
					awayBall = true;
				}else{
					homeScore = homeScore + touchDown;
					System.out.println("Home touch down!");
					System.out.println( "Home: " + homeScore + " Away: " + awayScore );
					homeBall = false;
					awayBall = true;
				}
			}
		}
 
		while (awayBall){
			double awayChance = Math.random();
			if (awayChance < 0.5){
				System.out.println("Away turnover!");
				System.out.println( "Home: " + homeScore + " Away: " + awayScore );
				homeBall = true;
				awayBall = false;
			}
			else if (0.5 <= awayChance){
				if (awayChance < 0.75){
					awayScore = awayScore + fieldGoal;
					System.out.println("Away field goal!");
					System.out.println( "Home: " + homeScore + " Away: " + awayScore );
					homeBall = true;
					awayBall = false;
				}else{
					awayScore = awayScore + touchDown;
					System.out.println("Away touch down!");
					System.out.println( "Home: " + homeScore + " Away: " + awayScore );
					homeBall = true;
					awayBall = false;
				}
			}
		}
		}
 
	}
 
}

Yes!!!!! It works perfectly! Except for the very end when at team reaches 50 they seem to just run a couple more plays for fun XD!

Console:

The away team won the coin toss!
Home turnover!
Home: 0 Away: 0
Away turnover!
Home: 0 Away: 0
Home touch down!
Home: 7 Away: 0
Away turnover!
Home: 7 Away: 0
Home turnover!
Home: 7 Away: 0
Away turnover!
Home: 7 Away: 0
Home touch down!
Home: 14 Away: 0
Away field goal!
Home: 14 Away: 3
Home touch down!
Home: 21 Away: 3
Away turnover!
Home: 21 Away: 3
Home turnover!
Home: 21 Away: 3
Away field goal!
Home: 21 Away: 6
Home touch down!
Home: 28 Away: 6
Away turnover!
Home: 28 Away: 6
Home touch down!
Home: 35 Away: 6
Away touch down!
Home: 35 Away: 13
Home turnover!
Home: 35 Away: 13
Away turnover!
Home: 35 Away: 13
Home turnover!
Home: 35 Away: 13
Away turnover!
Home: 35 Away: 13
Home field goal!
Home: 38 Away: 13
Away touch down!
Home: 38 Away: 20
Home field goal!
Home: 41 Away: 20
Away turnover!
Home: 41 Away: 20
Home turnover!
Home: 41 Away: 20
Away turnover!
Home: 41 Away: 20
Home touch down!
Home: 48 Away: 20
Away field goal!
Home: 48 Away: 23
Home turnover!
Home: 48 Away: 23
Away turnover!
Home: 48 Away: 23
Home field goal!
Home: 51 Away: 23
Away touch down!
Home: 51 Away: 30
Final Score: Home 51, Away 30
Home touch down!
Home: 58 Away: 30
Away touch down!
Home: 58 Away: 37

Is there a statement that could easily just end the program because gameInProgress = false; doesn't seem to complete the job.

Your test for the end of the game is in the wrong place. Shouldn't it be AFTER either team scores? Other than that, great job moving things around and following simple directions!

Yep. I fixed it everything. Works Perfectly. Thanks for the help Greg! That was my first "big" program I did on my own and it turned out well. Friend request sent. SOLVED!