Question

我正在编写一些代码来计算层次结构的某种估值（以点数表示）。我正在使用带有扫描器的switch语句（声明为静态变量），并且由于某种原因，在每个boardTypes中，“y”和“n”情况不会中断;他们只是进入下一个boardType案例。我在这做错了什么？

System.out.println("Are they on board? (y/n)");
isOnBoard = s.nextLine();
switch (isOnBoard){
case "y":
    System.out.println("Chapter, regional, or international board? ");
    boardType = s.nextLine();
    switch (boardType){
    case "chapter":
        System.out.println("Are they chapter president? (y/n)");
        switch(s.nextLine()){
        case "y":
            totalPoints = chapterPres;
            break;
        case "n":
            totalPoints = chapterBoardMember;
            break;
        }
    case "regional":
        System.out.println("Are they regional president? (y/n)");
        switch(s.nextLine()){
        case "y":
            totalPoints = regionalPres;
            break;
        case "n":
            totalPoints = regionalExecutive;
            break;
        }
    case "international":
        System.out.println("Are they international president? (y/n)");
        switch(s.nextLine()){
        case "y":
            totalPoints = internationalPres;
            break;
        case "n":
            totalPoints = internationalExecutive;
            break;
        }
    case "n": break;
}

全部谢谢！

Answer 1

您缺少break个陈述 - 您使用{ }附上一个块的事实不会让它崩溃：

case "chapter":
    System.out.println("Are they chapter president? (y/n)");
    switch(s.nextLine()){
    case "y":
        totalPoints = chapterPres;
        break;
    case "n":
        totalPoints = chapterBoardMember;
        break;
    }
    break; // This was missing
case "regional":
    System.out.println("Are they regional president? (y/n)");
    switch(s.nextLine()){
    case "y":
        totalPoints = regionalPres;
        break;
    case "n":
        totalPoints = regionalExecutive;
        break;
    }
    break; // This was missing
case "international":
    System.out.println("Are they international president? (y/n)");
    switch(s.nextLine()){
    case "y":
        totalPoints = internationalPres;
        break;
    case "n":
        totalPoints = internationalExecutive;
        break;
    }
    break; // This was missing
case "n": break;

Answer 2

switch秒内您有switch个。 break语句突破了内部语句，但不是外部语句。外部的你也需要break：

switch (boardType){
    case "chapter":
        System.out.println("Are they chapter president? (y/n)");
        switch(s.nextLine()){
        case "y":
            totalPoints = chapterPres;
            break;  // <== Only breaks out of the inner `switch(s.nextLine())`
        case "n":
            totalPoints = chapterBoardMember;
            break;  // <== Only breaks out of the inner `switch(s.nextLine())`
        }
        break; // <=== Need this (and so on) to break out of outer switch
    case "regional":
        // ...

Answer 3

你从内部情况突然而不是从外部突破。你也必须休息一下外壳。

Answer 4

You can change your code with break statement for outer cases too   

------------------------------------------------------------------------------


 System.out.println("Are they on board? (y/n)");
    isOnBoard = s.nextLine();
    switch (isOnBoard){
    case "y":
        System.out.println("Chapter, regional, or international board? ");
        boardType = s.nextLine();
        switch (boardType){
        case "chapter":
            System.out.println("Are they chapter president? (y/n)");
            switch(s.nextLine()){
            case "y":
                totalPoints = chapterPres;
                break;
            case "n":
                totalPoints = chapterBoardMember;
                break;
            }
    break;
        case "regional":
            System.out.println("Are they regional president? (y/n)");
            switch(s.nextLine()){
            case "y":
                totalPoints = regionalPres;
                break;
            case "n":
                totalPoints = regionalExecutive;
                break;
            }
    break;
        case "international":
            System.out.println("Are they international president? (y/n)");
            switch(s.nextLine()){
            case "y":
                totalPoints = internationalPres;
                break;
            case "n":
                totalPoints = internationalExecutive;
                break;
            }
    break;
        case "n": break;
    }

为什么这个开关块不工作？

4 个答案: