Question

Write a program to score the paper-rock-scissor game. Each of two users types in either P,R or S. The program call function Find winner to announces the winner. For determining the winner: Paper covers rock, Rock breaks scissors, Scissors cut paper, or it is a tie. Be sure to allow the users to use lower case as well as uppercase letters. Your program should include a loop that lets the user play again until the user says she or he is done.

The function prototype is:

public static int FindWinner (char p1, char p2);

java program

Answer 1

Please find the code below:

RockPaperScissorsChoice.java

package classes4;

import java.util.Random;
import java.util.Scanner;

//This class asks the user to write a method doing the comparison
//of two hands for the game Rock, Paper, Scissors.
public class RockPaperScissorsChoice {
   //Create enumeration constants for the types of hands.

   //Create enumeration constants for the outcomes of who wins.
   public enum Winner {
       USER, TIE, USER2
   }

   //Additional private member variables used in the game playing class.
   private Scanner scan = new Scanner(System.in);

   //Constructor that takes the command line arguments to look
   //for an integer random seed to start the computer's hand.
   public RockPaperScissorsChoice() {}

   //Method to play a round of RPS.
   void play() {
       //TODO: Get a hand from the computer by calling getComputerHand();
       String choice;
       while(true){
           char userHand1 = getUserHand("User1 : ");
           //TODO: Get a hand from the user by calling getUserHand();
           char userHand2 = getUserHand("User2 : ");
           //TODO: Pass the return values from those two methods to printWinner().
           printWinner(userHand1, userHand2);
           System.out.print("Continue [yes/no] : ");
           choice = scan.nextLine();
           if(choice.length()!=0 && choice.toLowerCase().startsWith("y")){
               continue;
           }else{
               break;
           }
       }
   }

   //Compute and print the winner of the match, given a hand for each
   //of computer and user. Handle the error case of indeterminate winner.
   void printWinner(char computerHand, char userHand) {
       int winner = FindWinner(computerHand, userHand);
       System.out.println("Player 1 : " + computerHand + " vs Player 2 : " + userHand);
       switch (winner) {
       case 'P':
           System.out.println("Player-2 wins.");
           break;
       case 'T':
           System.out.println("It's a tie.");
           break;
       case 'U':
           System.out.println("Player-1 wins.");
           break;
       default:
           System.out.println("Error, no one wins!");
           break;
       }
   }

   //Evaluate a pair of hands to see which wins. Use the typical ordering of
   //rock > scissors > paper > rock.
   public static int FindWinner (char userHand, char userHand2){
       if(userHand=='S' && userHand2=='P' || userHand=='P' && userHand2=='R'
               || userHand == 'R' && userHand2=='S'
               ){
           return 'U';
       }else if(userHand==userHand2){
           return 'T';
       }else{
           return 'P';
       }

   }

   //Get a user hand from the scanner.
   private char getUserHand(String user) {
       System.out.print(user+"What's your hand, rock/paper/scissors : ");
       String userInput = scan.nextLine();
       if (userInput.equalsIgnoreCase("r")) {
           return 'R';
       } else if (userInput.equalsIgnoreCase("p")) {
           return 'P';
       } else if(userInput.equalsIgnoreCase("s")){
           return 'S';
       }else{
           System.out.println("Invalid entry. Setting hand to paper");
           return 'P';
       }
   }

   //Method to set up the Main object, apply a computer hand,
   //prompt for user hand, evaluate the hands, and print result.
   //Run from the command line with no arguments, or with a single
   //positive long integer to seed the random number generator.
   public static void main(String[] args) {
       RockPaperScissorsChoice rpsPlayer = new RockPaperScissorsChoice();
       rpsPlayer.play();
   }
}

output: