Java 要创建if语句，然后是几个其他if语句，最后是一个"；“捕获全部”；else语句

创造一个“海盗对话”，选择左手或右手。我希望它对“left”和“right”的不同拼写做出肯定的回答（正如您将在代码中看到的），但是，当我为所有不是“right”或“left”的输入添加最后的“else”代码时，它会给我一个“java.lang.Error”，这是无法访问的代码。在添加最后一个“else”语句之前，我测试了我的代码，它的工作方式与我所希望的一样，再次添加“else”语句，它给出了相同的错误

（我也非常感谢关于如何改进我的代码的提示和反馈，这是我完全自己创建的第二个项目）

不管怎样，代码如下：

package myOwn;

import java.util.Scanner;

public class myArms {

static Scanner sc2 = new Scanner(System.in);

public static void main(String[] args) {
    armInput();
}

public static void armInput() {
    System.out.println("Behold the arms! Which hand holds the secret item?");
    String answer = sc2.nextLine();
    System.out.println(armOpener(answer));
}

public static String armOpener(String answer) {
    if(answer.equals("left")) {
        return "Aha! Indeed the gemstone was hidden in the left hand. Now...";
    }else if(answer.equals("Left")) {
        return "Aha! Indeed the gemstone was hidden in the left hand. Now...";
    }else if(answer.equals("LEFT")) {
        return "Aha! Indeed the gemstone was hidden in the left hand. Now...";
    }else if(answer.equals("right")) {
        return "Bummer! The treasure was in the other hand. Easy for me to say, huh? What if there wasn't a treasure from the start of? Who knows...";
    }else if(answer.equals("Right")) {
        return "Bummer! The treasure was in the other hand. Easy for me to say, huh? What if there wasn't a treasure from the start of? Who knows...";
    }else if(answer.equals("RIGHT")) {
        return "Bummer! The treasure was in the other hand. Easy for me to say, huh? What if there wasn't a treasure from the start of? Who knows...";
    }else {
        return "Did you not hear me boy? I'm asking you, which hand?!";
    }
    return answer;
}

}

---

“return answer；”这一行以红色下划线结尾。如果我删除最后一个“else”语句，红色下划线就会消失。

这是因为在所有

if

语句之后，您有一个

return

语句，它将永远不会执行，因为如果

if

语句都不匹配，它将转到

else

语句并在那里终止

如果不满足任何条件，您可以根据预期的返回值删除

返回

行或最终的

else

...
public static String armOpener(String answer) {
    String ans = answer.toLowerCase();

    if (ans.equals("left")) {
        return "Aha! Indeed the gemstone was hidden in the left hand. Now...";
    } else if (ans.equals("right")) {
        return "Bummer! The treasure was in the other hand. Easy for me to say, huh? What if there wasn't a treasure from the start of? Who knows...";
    }

    return "Did you not hear me boy? I'm asking you, which hand?!";
}
...

此外，您似乎正在为单词的不同字母大小写返回相同的值（

right

和

right

），可以通过比较变量的小写值在一条语句中进行处理。然后，当您有多个这样的if时，您可以通过使用

开关

语句来简化：

...
public static String armOpener(String answer) {
    switch(answer.toLowerCase()) {
        case "left":
            return "Aha! Indeed the gemstone was hidden in the left hand. Now...";

        case "right":
            return "Bummer! The treasure was in the other hand. Easy for me to say, huh? What if there wasn't a treasure from the start of? Who knows...";

        default:
            return "Did you not hear me boy? I'm asking you, which hand?!";
    }
}
...

---

所以如果所有的

都不匹配，你想返回
答案
，还是想返回
“孩子，你没听见我说话吗？我在问你，哪只手？！”
。因为现在您的代码尝试同时执行这两项操作。无关：您可以通过调用而不是
equals
来简化代码。红色下划线可能表示“无法访问的代码”由于在
if
或
else
块中返回后，该语句永远无法执行，因此
if else
语句是详尽的，因此最后一个
返回答案将永远无法访问。顺便说一句，有一个
equalsIgnoreCase
方法可以代替
equals
，进行不区分大小写的比较。这将减少
if
语句的数量。我最后只删除了“return answer；”这一行，并使用“（answer.equalsIgnoreCase）”简化了代码，这导致最终结果与您的结果有些相似，但没有使用switch语句，我还不熟悉这一语句：）@estrio Great，至少你找到了一个适合你的解决方案。