為什么此開關塊不起作用？

Question

我正在編寫一些代碼來計算層次結構的某個評估（以點數表示）。 我在掃描器上使用了switch語句（聲明為靜態變量），由於某種原因，在每個boardType中，“ y”和“ n”的情況都不會中斷； 他們只是進入下一個boardType案例。 我在這里做錯了什么？

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;
}

謝謝大家！

Answer 1

您缺少break語句-用{ }括住一個塊的事實不會使其中斷：

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

您在switch s內有switch s。 break語句是從內部語句中發出的，而不是從外部語句中發出的。 您也需要break外部的：

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

您從內殼而不是外層突圍。 您還必須休息一下外殼。

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;
    }