想要创建 if 语句，然后是几个 else-if 语句，最后是一个“捕获所有”else 语句

Question

通过选择左手或右手的选项创建“海盗对话”。我希望它对“左”和“右”的不同拼写做出肯定的回答（正如您将在代码中看到的那样），但是，当我为所有不是“右”或“左”的输入添加最终的“其他”代码时，它给了我一个“java.lang.Error”，无法访问的代码。我在添加最终的“else”语句之前测试了我的代码，它按我的意愿工作，再次添加了“else”语句，它给了我同样的错误。

（我也很感激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;
}

}

“返回答案”行是以红色下划线结尾的那个。如果我删除最后一个“else”语句，红色下划线就会消失。

Answer 1

那是因为在你的所有if 语句之后，你有一个永远不会执行的return 语句，因为如果没有一个if 语句匹配，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return 行或最后的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，对于单词的不同字母大小写（right 和RIGHT），您似乎返回了相同的值，可以通过比较变量的小写值在一个语句中进行处理。然后当你有多个这样的 if 时，你可以通过使用 switch 语句来简化它：

...
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?!";
    }
}
...