Dice

Java Console App to roll dice and flip coins

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DiceApp

Rolling Dice

Users can choose to roll one or multiple dice.

if (numberOfTimesToRollDice == 1) Dice.rollOne(diceSelection);
if (numberOfTimesToRollDice > 1) Dice.rollMany(diceSelection, numberOfTimesToRollDice);

Flipping Coin

Users can also choose to flip one or multiple coins.

if (coinFlips == 1) Dice.flipOne();
if (coinFlips > 1) Dice.flipMany(coinFlips);

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Dice

Rolling Dice

Uses Java's ThreadLocalRandom to get a random number between 1 and the highest possible roll (based on dice type).

public static int getRoll(int diceType){
      return ThreadLocalRandom.current().nextInt(1, diceType + 1);
}

If only rolling a single dice, the result is displayed.

public static void rollOne(int dice){
      // ... validation for entered dice type
      UserOutput.printRoll(getRoll(dice));
}

If rolling multiple dice, each roll is printed on a new line, and then the sum total of all rolls is displayed.

public static void rollMany(int dice, int increment){
      // ... validation for entered dice type and number of times to roll dice
      int total = 0;
      for (int i = 1; i <= increment; i++) {
            int roll = getRoll(dice);
            UserOutput.printRoll(roll, i);
            total += roll;
      }
      UserOutput.printRollTotal(total);
}

Flipping Coin

Calls the getRoll function to get a random number between 1 and 2 and assigns 'Heads' or 'Tails' based on the return.

static final int COIN = 2;
public static String flipCoin( ){
      int randomNum = Dice.getRoll(COIN);
      return (randomNum == 1) ? "Heads" : "Tails";
}

If only flipping a single coin, the result is displayed.

public static void flipOne(){
      // ...
      UserOutput.printFlip(flipCoin());
}

If flipping multiple coins, each coin flip is printed on a new line, and the total for 'Heads' and 'Tails' is displayed.

public static void flipMany(int increment){
      // ... validation for number of times to flip coin
      int headsTotal = 0;
      int tailsTotal = 0;
      for (int i = 1; i <= increment; i++) {
            String flip = flipCoin();
            UserOutput.printFlip(flip, i);
            if (flip.equals("Heads")) headsTotal++;
            if (flip.equals("Tails")) tailsTotal++;
      }
      UserOutput.printFlipTotals(headsTotal, tailsTotal);
 }

Validating User Input

The entered dice type must be a dice type commonly used used in tabletop RPG games (D4, D6, D8, D10, D12, D20, & D100).

// static finals created for each dice type
public static boolean validateDice(int dice){
      boolean isValid = (dice == D4 || 
                         dice == D6 || 
                         dice == D8 || 
                         dice == D10 || 
                         dice == D12 || 
                         dice == D20 || 
                         dice == D100);
      if (!isValid) UserOutput.printDiceTypeError(dice);
      return isValid;
}

If rolling multiple dice or flipping multiple coins, the entered number of times to roll dice or flip coins must be between 1 and 20.

public static boolean validateIncrement(int type, int i){
      // set minimum and maximum values for increment
      int minimumIncrement = 1;
      int maximumIncrement = 20;

      boolean isValid = (i >= minimumIncrement && i <= maximumIncrement);
      if (!isValid && type == COIN) UserOutput.printFlipTimesError();
      if (!isValid && type != COIN) UserOutput.printRollTimesError();
      return isValid;
}

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User Input

Uses Java Scanner to take in user input from the console.
Input string is stripped of leading and trailing whitespace and returned.

import java.util.Scanner;

public class UserInput {

    private static Scanner scanner = new Scanner(System.in);

    public static String getInput() {
        String input = scanner.nextLine().strip();
        return input;
    }
}

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User Output

Contains all the print statements used to display information to the console.
Text printed to the console is formatted using Java's String.format() as well as final values set in the FontColor class.
When rolling multiple dice, rolls are printed out in alternating white-grey-white pattern for easier reading.
When flipping multiple coins, 'Heads' is printed out in white and 'Tails' in grey for easier reading.

// FontColor.WHITE is dull white (grey), FontColor.RESET is bright white (white)
public static void printRoll(int roll, int i) {
      String increment = String.format("%2s", String.valueOf(i));
      String formattedRoll = String.format("%3s", String.valueOf(roll));
      if (i%2!=0) {
            System.out.println(FontColor.PURPLE + 
                               "Roll " + 
                               increment + 
                               ":   " + 
                               FontColor.RESET + 
                               formattedRoll);
      } else {
            System.out.println(FontColor.PURPLE + 
                               "Roll " + 
                               increment + 
                               ":   " + 
                               FontColor.WHITE + 
                               formattedRoll + 
                               FontColor.RESET);
      }
}

// FontColor.WHITE is dull white (grey), FontColor.RESET is bright white (white)
public static void printFlip(String flip, int i) {
      String increment = String.format("%2s", i);
      if (flip.equals("Heads")) {
            System.out.println(FontColor.PURPLE + 
                               "Flip " + 
                               increment + 
                               ":   " + 
                               FontColor.RESET + 
                               flip);
      } else {
            System.out.println(FontColor.PURPLE + 
                              "Flip " + 
                              increment + 
                              ":   " + 
                              FontColor.WHITE + 
                              flip + 
                              FontColor.RESET);
      }
}