Question

我创建了这个程序无限次地运行，要求用户输入一个选项（摇滚或纸张或剪刀），这似乎工作正常。问题是别的......如果或者......如果....满足。无论我给它输入什么，只需在else语句中输出else语句，（输入有效选项）。我无法发现我犯了如此错误的错误链接下面的代码.....提前感谢。

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

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

        Scanner input = new Scanner(System.in);
        Random number = new Random();

        String rps[] = {"rock", "paper", "scissor"};
        String player;
        String ai;
        int rand, pscore=0, aiscore=0;

        while(1 < 2){
        System.out.println("Take your pick \nrock \npaper \nscissor");
        player = input.nextLine();

        rand = number.nextInt(3);
        ai = rps[rand];

        System.out.println(ai);

        if(player == ai){
            pscore+=0;
            aiscore+=0;
            System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
            System.out.print("\n");
            continue;
        }else{
            if(player == "rock" && ai == "paper"){
                aiscore+=1;
                pscore+=0;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else if(player == "rock" && ai == "scissor"){
                pscore+=1;
                aiscore+=0;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else if(player == "paper" && ai == "rock"){
                pscore+=1;
                aiscore+=0;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else if(player == "paper" && ai == "scissor"){
                aiscore+=1;
                pscore+=0;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else if(player == "scissor" && ai == "rock"){
                aiscore+=1;
                pscore+=0;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else if(player == "scissor" && ai == "paper"){
                aiscore+=0;
                pscore+=1;
                System.out.println("Your opponent chose " + ai + "\tYour score= "+ pscore + "\tOpponents score = "+aiscore);
                System.out.print("\n");
                continue;
            }else{
                System.out.println("Enter a valid choice");
                System.out.print("\n");
                continue;
            }
        }
        }


    }
}

Answer 1

在java中，==测试引用相等性：如果两个对象实际上是同一个对象。两个包含相同字符的字符串将无法通过此检查，这就是您的逻辑中发生的事情。

请参阅How do I compare strings in Java?

Answer 2

而不是：

if(player == "rock" && ai == "paper"){
    ...
}

使用

if(player.equals("rock") && ai.equals("paper")){
   ...
}

这将适用于比较字符串的所有代码片段。

调试我的简单java游戏（Rock Paper Scissor）

2 个答案: