Question

Greetings Stack Overflow用户，今晚我来找你，帮助我创建一个Java程序。我对Java比较新，所以请原谅我对这个主题的无知。我制作了一个Java程序，它是一个“Rock”“Paper”“Scissors”游戏，其中一个语句中似乎有错误。

import java.util.Scanner;

public class TheAntlers {
public static void main(String[] args) {

    int playerHumanWins = 0;
    int playerComputerWins = 0;
    int numberOfTies = 0;
    int computerResult;

    Scanner input = new Scanner(System.in);

    while(true) {

        String startGame;
        String playerHuman;
        String playerComputer = " ";

        System.out.print("Do you want to play \"Rock\", \"Paper\", \"Scissors\"? (Y/N): ");
        startGame = input.nextLine();

        startGame = startGame.toUpperCase();

        if(startGame.equals("N")) {
            System.out.println("NO!");
            break;
        }
        else if(! startGame.equals("Y")) {
            startGame = startGame.toLowerCase();
            System.out.println("Sorry, " + startGame + " is not a valid entry...");               
        }
        while(startGame.equals("Y")) {
            System.out.print("Please choose \"Rock\", \"Paper\", or \"Scissors\": ");
            playerHuman = input.nextLine();

            computerResult = (int)(Math.random() * 3);

            playerHuman = playerHuman.toUpperCase();

            if(computerResult == 1) {
                playerComputer = "ROCK";
            }
            else if(computerResult == 2) {
                playerComputer = "PAPER";
            }
            else if (computerResult == 3) {
                playerComputer = "SCISSORS";
            }

            switch (playerHuman) {
                case "ROCK" :
                    if(playerComputer.equals(playerHuman)) {
                    System.out.println("Tie you both picked \"ROCK\"");
                    numberOfTies++;
                }
                    else if(playerComputer.equals("PAPER")) {
                        System.out.println("Computer wins!");
                        playerComputerWins++;
                    }
                    else {
                        System.out.println("You win, \"ROCK\" beats " + "\"" + playerComputer + "\"");
                        playerHumanWins++;
                        return;
                    }
                    break;
                case "PAPER" :
                    if(playerComputer.equals(playerHuman)) {
                    System.out.println("Tie you both picked \"PAPER\"");
                    numberOfTies++;
                }
                    else if(playerComputer.equals("ROCK")) {
                        System.out.println("You win, \"PAPER\" beats " + "\"" + playerComputer + "\"");
                        playerHumanWins++;
                        return;
                    }
                    else {
                        System.out.println("Sorry, the computer won!");
                        playerComputerWins++;
                    }
                    break;
                case "SCISSORS" :
                    if(playerComputer.equals(playerHuman)) {
                    System.out.println("Tie you both picked \"SCISSORS\"");
                    numberOfTies++;
                }
                    else if(playerComputer.equals("PAPER")) {
                        System.out.println("You win, \"SCISSORS\" beats " + "\"" + playerComputer + "\"");
                        playerHumanWins++;
                        return;
                    }
                    else {
                        System.out.println("Sorry, the computer won!");
                        playerComputerWins++;
                    }
                    break;
                default:
                    playerHuman = playerHuman.toLowerCase();
                    System.out.println("Sorry, " + playerHuman + " is not a valid entry..."); 
                    break;
            } 
        }
    }         
}
}

我面临的问题与中奖计算有关。当我运行程序并且我反复进入摇滚直到我获胜时，输出将是你赢了，“ROCK”击败“但是除了任何其他选项我得到你赢了，”ROCK“击败“PAPER”

我的问题是，为什么我在玩摇滚时会得到一个空的回调？

* 此外，如果您愿意指出任何其他建议，以帮助一个很棒的新手。 *

Answer 1

Math.random() * 3是一个至少为0且小于3的数字。

将其转换为int后，它为0,1或2。

        if(computerResult == 0) {
            playerComputer = "ROCK";
        }
        else if(computerResult == 1) {
            playerComputer = "PAPER";
        }
        else if (computerResult == 2) {
            playerComputer = "SCISSORS";
        }

建议：

简明扼要。你可以改变

String startGame;
startGame = input.nextLine();
startGame = startGame.toUpperCase();

到

String startGame = input.nextLine().toUpperCase();

当您不必滚动和滚动时，它更具可读性。

另外，请知道equalsIgnoreCase()存在。

Answer 2

这不是一个完整的新手，但我会使用以下代码为游戏建模：

enum Choice { ROCK, PAPER, SCISSORS }

enum Result { COMPUTER_WINS, TIE, HUMAN_WINS }

Result decide(Choice computer, Choice human) {
  if (human == computer) {
    return Result.TIE;
  } else if (…) {
    …
  }
}

通过这种方式，您可以使用部分代码来处理游戏本身，而其他一些代码则处理用户交互。

Answer 3

你会发现（int）（Math.random（）* 3）有时会导致0而从不会导致3，这就是给你空白的结果，因为你没有0的结果。

具体来说，当Math.random（）返回小于.33

时

Java - 嵌套While循环

3 个答案: