C# random function to roll 3 dice

Question

1.00/5 (1 vote)

See more:

Hello,
How can I start a function that will randomly generate integers for 3 dice when I roll them at the same time?
My aim is to get the 3 numbers and put them beside each other (larger to smaller), for example if I roll 3,1,4 I need to display 431. I started the code by not sure how to continue. I created 3 labels and 3 textboxes for the 3 dice and a "Roll" button that will display random results but I am stuck and don't know how to proceed!
Can you please give me a push?
Thanks

What I have tried:

Random rnd = new Random();
int dice1 = rnd.Next(1,6); // creates a number between 1 and 6 from dice 1
int dice2 = rnd.Next(1,6);   // creates a number between 1 and 6 from dice 2
int dice3 = rnd.Next(1,6);  // creates a number between 1 and 6 from dice 3

Posted 12-Oct-18 4:31am

Member 14017552

Updated 12-Oct-18 4:56am

Add a Solution

Comments

MadMyche 12-Oct-18 10:52am

What are the results of this? Does it work as intended?

[no name] 12-Oct-18 11:00am

Maybe it's my "version", but you may find you need to use .Next(1,7) to get numbers between 1 and 6!

You can put your results in a List<int>, use LINQ to sort, and then copy each value to its respective text box.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2018-10-12T04:52:00

Solution 1

Start by moving the Random instance out of the method, and putting it into a class level variable:

private Random rnd = new Random();
void MyMethod()
    {
    int dice1 = rnd.Next(1,6); // creates a number between 1 and 6 from dice 1
    int dice2 = rnd.Next(1,6);   // creates a number between 1 and 6 from dice 2
    int dice3 = rnd.Next(1,6);  // creates a number between 1 and 6 from dice 3
    ...
    }

The reason for that is that Random is initialized with the system clock, so you don't want to create them over and over, or you will get the same sequence if you call your method too quickly. Making it class level, means it is created once, so you don't get that repetition.

Then, look at the definition of the Next method, and you will see that the upper bound is exclusive - the value returned will never equal it - so you need to add one in order to get a fair roll on a six sided die:

private Random myDie = new Random();
public int RollStandardDie()
    {
    return myDie.Next(1, 6 + 1);
    }

Then call RollStandardDie three times to get your values, and sort them. The easiest way is like this:

private Random myDie = new Random();
public int RollStandardDie()
    {
    return myDie.Next(1, 6 + 1);
    }
private void MyButton_Click(object sender, EventArgs ew)
    {
    int[] dice = new int[3];
    for (int i = 0; i < dice.Length; i++)
        {
        dice[i] = RollStandardDie();
        }
    Array.Sort(dice);

Then just feed your values into your Labels or TextBoxes:

label1.Text = dice[0].ToString();
TextBox2.Text = dice[1].ToString();

Posted 12-Oct-18 4:52am

OriginalGriff

Comments

[no name] 12-Oct-18 11:56am

The "purist" / OCD in me wants to use "parallel" throws because the requirement is to "roll 3 dice".

(For the I Ching, you can reduce "3 coin" tosses to one of 4 numbers).

OriginalGriff 12-Oct-18 11:59am

Your OCD is dangerous: Random.Next is decidedly not thread safe! :laugh:
https://blogs.msdn.microsoft.com/pfxteam/2009/02/19/getting-random-numbers-in-a-thread-safe-way/

[no name] 12-Oct-18 12:27pm

It never occurred to me to use the "same" Random for parallel operations.

One creates multiple instances in different points in time (if not explicitly "seeding").

OriginalGriff 12-Oct-18 12:43pm

And on a multiple core machine, that means they all probably start from the same seed ... or you have to set up an array of the buggers! :laugh:

[no name] 12-Oct-18 13:12pm

They're seeded when created; you don't "create" them at the same time.

The parallel operation is the "rolling".

(And you can re-initialize, randomly, while waiting for the user to hit the button).

You create state machines; not just an "array of randoms".

Member 14017552 12-Oct-18 20:28pm

Thanks OriginalGriff,

Here is the latest code as per your advice, thanks... but when I add the last line to show the result I am getting an error!
---------------
using System.Windows.Forms;

namespace DiceGame
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private Random myDice = new Random();
public int RollDice()
{
return myDice.Next(1, 6 + 1);
}

private void Play_Button_Click(object sender, EventArgs e)
{
int[] dice = new int[3];
for (int i = 0; i < dice.Length; i++)
{
dice[i] = RollDice();
}

Array.Sort(dice);

Dice1_input.Text = dice[0].ToString();
Dice2_input.Text = dice[1].ToString();
Dice3_input.Text = dice[2].ToString();

Player1_Result.Text = ("Player 1: {0}{1}{2}", Dice1_input, Dice2_input, Dice3_input);

}

}
}
-----------------------------
Please see attached screenshot here https://imgur.com/a/6DgY5VE

Regards

OriginalGriff 13-Oct-18 5:09am

No. You want me to look at an error, you copy and paste it in - I'm not going off to look at a poor screenshot of an error message!

But at a guess ... What happened to "string.Format"?

Member 14017552 13-Oct-18 9:47am

Got it fixed, thanks for the tip and sorry for the screenshot.

If you don't mind me asking one more question:
Our second project is now to have two players and compare the results and say who wins. I copied and pasted the exact code and added Player 2 as well...

Dice1_input_Player1.Text = dice_Player1[0].ToString();
Dice2_input_Player1.Text = dice_Player1[1].ToString();
Dice3_input_Player1.Text = dice_Player1[2].ToString();

Dice1_input_Player2.Text = dice_Player2[0].ToString();
Dice2_input_Player2.Text = dice_Player2[1].ToString();
Dice3_input_Player2.Text = dice_Player2[2].ToString();

Player1_Result.Text = string.Format("Player 1: {0}{1}{2}", Dice1_input_Player1.Text, Dice2_input_Player1.Text, Dice3_input_Player1.Text);
Player2_Result.Text = string.Format("Player 2: {0}{1}{2}", Dice1_input_Player2.Text, Dice2_input_Player2.Text, Dice3_input_Player2.Text);

int P1R = Convert.ToInt32(Player1_Result.Text);
int P2R = Convert.ToInt32(Player2_Result.Text);

if (P1R >= P2R)
Console.Write("Player 1 Wins!");
else
Console.Write("Player 2 Wins!");

-----
but when I run the code the "Play" Button becomes un-clickable and I am getting the error: "System.FormatException: Input string was not in a correct format."

and it shows the error on
int P1R = Convert.ToInt32(Player1_Result.Text);
int P2R = Convert.ToInt32(Player2_Result.Text);

tried a lot but can't figure it out, can you please help?
Sorry, I am still very newbie to programming and still in the learning curve...
Thanks

OriginalGriff 13-Oct-18 10:01am

Look at your code.
Use the debugger if you have to, but ... look at what is in Player_1_Result.Text. Is that a number?

Member 14017552 13-Oct-18 10:20am

I did and getting "you must rename an identifier" I just can't figure it out!
Player_1_Result.Text is a String and we should convert it to Int in order to use it in IF statement.
Please correct if I am wrong,
Thanks

OriginalGriff 13-Oct-18 10:44am

Yes, it's a string. And yes, you want a number. But ... what did you put in the string?

Think about it for a minute (use the debugger if you aren't sure, it will show you EXACTLY what the string contains).
Then think : What number does that equate to?

Member 14017552 13-Oct-18 13:04pm

The problem is that I am not getting any error in the "Error List" so the program is running but when I click on "Play" it freezes and pops up the error message "System.FormatException: 'Input string was not in a correct format. I ran the debugger but not getting anywhere. Please man, give me the push.

OriginalGriff 13-Oct-18 17:32pm

When you use the debugger it will stop when you get the exception and let you look at what is in the variables when the problem occurred. Heck, it'll let you change the code and try again from that point or any other. Get used to the debugger - it is your best friend in the dev world, and can save you HUGE amounts of time and effort!

Member 14017552 · Answer 2 · 2018-10-12T04:57:00

Solution 2

Thanks a lot for helping... is there a way to do the last bit without using an array? I know it might be a long solution but I just want to compare and learn the difference.
Thanks again

Posted 12-Oct-18 4:57am

Member 14017552

Comments

MadMyche 12-Oct-18 11:07am

Instead of assigning the values to an array; you could use a StringBuilder and append on each die roll

OriginalGriff 12-Oct-18 11:34am

Yes, but it's easier to sort with an array - and more flexible in the future.
But you can do it with "normal" code, it's just longer and more hassle:

if (a > c)
  {
  temp = a;
  a = c;
  c = temp;
  }
if (a > b)
  {
  temp = a;
  a = b;
  b = temp;
  }
if (b > c)
  {
  temp = b;
  b = c;
  c = temp;
  }

It gets a lot more long winded for four and on up!

Richard Deeming 12-Oct-18 13:39pm

If you want to reply to a solution, click the "Have a Question or Comment?" button under that solution.

DO NOT post your comment as a new "solution".