Java port of BASIC Craps

2025-12-22 23:26:40 -08:00 · 2022-01-14 01:43:24 -08:00
parent 8245d7badb
commit b4c8bfc9c8
1 changed files with 125 additions and 0 deletions
--- a/29_Craps/java/src/Craps.java
+++ b/29_Craps/java/src/Craps.java
@@ -0,0 +1,125 @@
+import java.util.Random;
+import java.util.Scanner;
+
+/**
+ *  Port of Craps from BASIC to Java 17.
+ */
+public class Craps {
+  public static final Random random = new Random();
+  
+  public static void main(String[] args) {
+    System.out.println("""
+                                                            CRAPS
+                                          CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY
+                                              
+                                              
+                           2,3,12 ARE LOSERS; 4,5,6,8,9,10 ARE POINTS; 7,11 ARE NATURAL WINNERS.
+                           """);
+    double winnings = 0.0;
+    do {
+      winnings = playCraps(winnings);
+    } while (stillInterested(winnings));
+    winningsReport(winnings);
+  }
+
+  public static double playCraps(double winnings) {
+    double wager = getWager();
+    System.out.println("I WILL NOW THROW THE DICE");
+    int roll = rollDice();
+    double payout = switch (roll) {
+      case 7, 11 -> naturalWin(roll, wager);
+      case 2, 3, 12 -> lose(roll, wager);
+      default -> setPoint(roll, wager);
+    };
+    return winnings + payout;
+  }
+
+  public static int rollDice() {
+    return random.nextInt(1, 7) + random.nextInt(1, 7);
+  }
+
+  private static double setPoint(int point, double wager) {
+    System.out.printf("%1$ d IS THE POINT. I WILL ROLL AGAIN%n",point);
+    return makePoint(point, wager);
+  }
+
+  private static double makePoint(int point, double wager) {
+    int roll = rollDice();
+    if (roll == 7)
+      return lose(roll, wager);
+    if (roll == point)
+      return win(roll, wager);
+    System.out.printf("%1$ d - NO POINT. I WILL ROLL AGAIN%n", roll);
+    return makePoint(point, wager);  // recursive
+  }
+
+  private static double win(int roll, double wager) {
+    double payout = 2 * wager;
+    System.out.printf("%1$ d - A WINNER.........CONGRATS!!!!!!!!%n", roll);
+    System.out.printf("%1$ d AT 2 TO 1 ODDS PAYS YOU...LET ME SEE...$%2$3.2f%n",
+                      roll, payout);
+    return payout;
+  }
+
+  private static double lose(int roll, double wager) {
+    String msg = roll == 2 ? "SNAKE EYES.":"CRAPS";
+    System.out.printf("%1$ d - %2$s...YOU LOSE.%n", roll, msg);
+    System.out.printf("YOU LOSE $%3.2f%n", wager);
+    return -wager;
+  }
+
+  public static double naturalWin(int roll, double wager) {
+    System.out.printf("%1$ d - NATURAL....A WINNER!!!!%n", roll);
+    System.out.printf("%1$ d PAYS EVEN MONEY, YOU WIN $%2$3.2f%n", roll, wager);
+    return wager;
+  }
+
+  public static void winningsUpdate(double winnings) {
+    System.out.println(switch ((int) Math.signum(winnings)) {
+      case 1 -> "YOU ARE NOW AHEAD $%3.2f".formatted(winnings);
+      case 0 -> "YOU ARE NOW EVEN AT 0";
+      default -> "YOU ARE NOW UNDER $%3.2f".formatted(-winnings);
+    });
+  }
+
+  public static void winningsReport(double winnings) {
+    System.out.println(
+        switch ((int) Math.signum(winnings)) {
+          case 1 -> "CONGRATULATIONS---YOU CAME OUT A WINNER. COME AGAIN!";
+          case 0 -> "CONGRATULATIONS---YOU CAME OUT EVEN, NOT BAD FOR AN AMATEUR";
+          default -> "TOO BAD, YOU ARE IN THE HOLE. COME AGAIN.";
+        }
+    );
+  }
+
+  public static boolean stillInterested(double winnings) {
+    System.out.print(" IF YOU WANT TO PLAY AGAIN PRINT 5 IF NOT PRINT 2 ");
+    int fiveOrTwo = (int)getInput();
+    winningsUpdate(winnings);
+    return fiveOrTwo == 5;
+  }
+
+  public static double getWager() {
+    System.out.print("INPUT THE AMOUNT OF YOUR WAGER. ");
+    return getInput();
+  }
+
+  public static double getInput() {
+    Scanner scanner = new Scanner(System.in);
+    System.out.print("> ");
+    while (true) {
+      try {
+        return scanner.nextDouble();
+      } catch (Exception ex) {
+        try {
+          scanner.nextLine(); // flush whatever this non number stuff is.
+        } catch (Exception ns_ex) { // received EOF (ctrl-d or ctrl-z if windows)
+          System.out.println("END OF INPUT, STOPPING PROGRAM.");
+          System.exit(1);
+        }
+      }
+      System.out.println("!NUMBER EXPECTED - RETRY INPUT LINE");
+      System.out.print("> ");
+    }
+  }
+}