CODEWITHSUNDEEP
javaswitch-statement
Cooky Kao
Cooky Kao

Reputation: 43

A Java code about scissor-rock-paper game

I’ve learned Java for 1 month. I have a question about my code. There is something wrong.If I press 0, the outcomes only has "Computer win" and "Tie" two situation. So as I press 1 and 2, it only comes out two. What's wrong in here ?

import java.util.Scanner;
public class Hm3 {
public static void main (String[] args) {
    int Computer=0,Player=0,tie=0,compic=0,pscore=0;tie=0;
    int end = 0;
    Scanner scan = new Scanner(System.in);
    while (end < 3) {
        System.out.print("Enter 0 for Scissors, 1 for Rock, and 2 for Paper : ");
        pscore = scan.nextInt();
        compic = (int)(Math.random()*2);

        switch (pscore){            
        case 0 :
            if (compic == 0){
                System.out.println("Tie");
                tie++;
            }else if (compic == 1){
                System.out.println("Computer Win");
                Computer++;
            }else{
                System.out.println("Player Win");
                Player++;
                end++;
            }
            break;
        case 1 :
            if (compic == 0){
                System.out.println("Player Win");
                Player++;
                end++;
            }else if (compic == 1){
                System.out.println("Tie");
                tie++;
            }else{
                System.out.println("Computer Win");
                Computer++;
            }break;
        case 2 :
            if (compic == 0){
                System.out.println("Computer Win");
                Computer++;
            }else if (compic == 1){
                System.out.println("Player Win");
                Player++;
                end++;
            }else{
                System.out.println("Tie");
                tie++;
            }break;
        default :               
            System.out.println("The wrong value");              
            break;
        }      
  }
    System.out.println("");
    System.out.println("The player wins : " + Player);
    System.out.println("The computer wins : " + Computer);
    System.out.println("Tie : " + tie);
 }
}

Upvotes: 0

Views: 13893

Answers (3)

Dan Simmons
Dan Simmons

Reputation: 116

Yes I also believe that the problem is with your random number generation. When dealing with integers I prefer to use this method because there is no rounding or casting involved:

Random random = new Random(); //create a random object

random.nextInt(3); //will return a random integer from 0 to 2

The number in the parenthesis of the nextInt() method is the range if you want to go from 1 to 3 just alter it to

random.nextInt(3) + 1;

Upvotes: 3

Julian Fondren
Julian Fondren

Reputation: 5619

You've been given the answer, and this isn't code review, but I can't fit this suggestion in a comment. Rather than three very similar sub-switches of a switch (which is what you effectively have, just with if-else), you can decide this with a single switch by offsetting the computer's choice by a number of bits (2 is all you need to encode three choices, but 4 is more convenient when you must use hexadecimal rather than binary literals) and ORing it with the player's choice to produce a number that encodes both moves.

// 0:scissors, 1:rock, 2:paper
private String winner(int player, int computer) {
  switch (player | (computer<<4)) {
    case 0:
    case 0x11:
    case 0x22:
      return "Tie";
    case 0x02:  // computer:scissors, player:paper
    case 0x10:
    case 0x21:
      return "Computer wins";
    case 0x01:
    case 0x12:
    case 0x20:
      return "Player wins";
    default:
      return "error";
  }
}

Upvotes: 0

Diego
Diego

Reputation: 18359

You are generating random integers from 0 to 1, not from 0 to 2. To fix, do Math.random()*3

Upvotes: 2

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