Question

我的代码导致异常..你能帮我发现我的问题吗？

import java.util.Scanner; 
import java.util.Random; 
class apples {

    public static void main(String[] args){
    Scanner SPS = new Scanner(System.in);
    System.out.println("Choose:\tstone,paper or scissors");
    SPS.hasNext();

    Random rand = new Random(2);

    int scissors = rand.nextInt(0);
    int stone = rand.nextInt(1);
    int paper = rand.nextInt(2);

    System.out.println((SPS.hasNext("scissors")||SPS.hasNext("stone")||SPS.hasNext("paper"))? null:"go play away from here");

    if(rand.nextInt() == 0 && SPS.hasNext("scissors")){
        System.out.println("scissors");
        System.out.println("You tie");

    }else if(rand.nextInt() == 0 && SPS.hasNext("stone")){

        System.out.println("scissors");
        System.out.println("You lose");

    }else if(rand.nextInt() == 0 && SPS.hasNext("paper")){

        System.out.println("scissors");
        System.out.println("You won");


    }else if(rand.nextInt() == 1 && SPS.hasNext("stone")){
        System.out.println("stone");
        System.out.println("You tie");

    }else if(rand.nextInt() == 1 && SPS.hasNext("scissors")){

        System.out.println("stone");
        System.out.println("You won");

    }else if(rand.nextInt() == 1 && SPS.hasNext("paper")){

        System.out.println("stone");
        System.out.println("You lose");

    }else if(rand.nextInt() == 2 && SPS.hasNext("paper")){
        System.out.println("paper");
        System.out.println("You tie");

    }else if(rand.nextInt() == 2 && SPS.hasNext("stone")){

        System.out.println("paper");
        System.out.println("You won");

    }else if(rand.nextInt() == 2 && SPS.hasNext("scissors"))

        System.out.println("paper");
        System.out.println("You lose");  
    }
}

和结果

Choose: stone,paper or scissors
stone
Exception in thread "main" java.lang.IllegalArgumentException: n must be positive
    at java.util.Random.nextInt(Unknown Source)
    at stone.paper.scissors.apples.main(apples.java:20)

Answer 1

嗯，你的问题在这里：

int scissors = rand.nextInt(0);

因为，如异常中所述，0不是正数。

您想要做的是：

int scissors = 0;
int stone = 1;
int paper = 2;

并在比较后使用变量：

if (!SPS.hasNext("(scissors|stone|paper)")) {
    System.out.println("go play away from here");
} else {

    int randomChoice = rand.nextInt(3);
    String userChoice = SPS.next();

    if(randomChoice == scissors && userChoice.equals("scissors")){
        System.out.println("scissors");
        System.out.println("You tie");
    }else if(randomChoice == scissors && userChoice.equals("stone")){
        System.out.println("scissors");
        System.out.println("You lose");
    }else if(randomChoice == scissors && userChoice.equals("paper")){
        System.out.println("scissors");
        System.out.println("You won");
    }else if(randomChoice == stone && userChoice.equals("stone")){
        System.out.println("stone");
        System.out.println("You tie");
    }else if(randomChoice == stone && userChoice.equals("scissors")){
        System.out.println("stone");
        System.out.println("You won");
    }else if(randomChoice == stone && userChoice.equals("paper")){
        System.out.println("stone");
        System.out.println("You lose");
    }else if(randomChoice == paper && userChoice.equals("paper")){
        System.out.println("paper");
        System.out.println("You tie");
    }else if(randomChoice == paper && userChoice.equals("stone")){
        System.out.println("paper");
        System.out.println("You won");
    }else if(randomChoice == paper && userChoice.equals("scissors")) {
        System.out.println("paper");
        System.out.println("You lose");
    }
}

注意：我也更正了：

您错误地使用了rand
您错误地使用了Scanner
上一个else if的缺失括号。

什么是错的，我陷入了石头。剪刀和纸张游戏？

1 个答案: