Java 无限循环在程序中无法正常工作

此程序使用2D数组记录开放和保留的房间。该程序在开始和每次更改数组后显示2D数组。索引值表示房间编号，并为开放房间显示。预订房间显示预订房间的人的姓名。程序将继续运行，直到用户输入“Q”

对我来说，一切似乎都很好，除了在主方法中循环一次之后，即使用户没有输入“Q”，程序也停止运行。我也试过用while（true）来做，但它仍然不起作用。我真的希望有人能帮我

public static void main (String [] args)
{
    Scanner kb = new Scanner (in);
    out.print("Enter row size: ");
    int row = kb.nextInt();
    out.print("Enter column size: ");
    int col = kb.nextInt();
    kb.nextLine();
    String [][]rooms = roomInIt(row, col);
    printMatrix(rooms);
    String a="";


    for(;;)
    {
        out.print("Would you like to reserve or release a room? Type Q to exit ");
        a = kb.nextLine();

        if (a.equalsIgnoreCase("reserve"))
        {
            out.print("How many rooms would you like to reserve? ");
            int num = kb.nextInt();
            reserveRooms(rooms, num);
        }
        else if (a.equalsIgnoreCase("release"))
        {
            out.print("How many rooms would you like to release? ");
            int x = kb.nextInt();
            releaseRooms(rooms, x);
        }
        else if (a.equalsIgnoreCase("Q"));
            break;
    }
}

public static void printMatrix(String[][]rooms)
{

    for(int r=0; r<rooms.length; r++)
        {
            for (int c=0; c<rooms[r].length; c++)
                out.print("["+r+","+c+"] "+rooms[r][c]+"\t");
            out.println();
        }
}

public static String[][] roomInIt(int row, int col)
{
    String [][]rooms = new String [row][col];
    for(int r=0; r<rooms.length; r++)
        for (int c=0; c<rooms[r].length; c++)
            rooms[r][c]="open";
    return rooms;
}

public static void reserveRooms(String [][]room, int num)
{

    Scanner kb = new Scanner(in);
    for(int i=0; i<num; i++)
    {   
        out.print("Enter name: ");
        String name = kb.nextLine();
        out.print("Enter the room number (row and column separated by a space) ");
        int r=kb.nextInt();
        int c=kb.nextInt();
        kb.nextLine();
        while (r<0 || r>room.length || c<0 || c>room[r].length || !room[r][c].equals("open"))
        {
            out.print("Invalid room number. Enter another room number (row and column separated by a space) ");
            r=kb.nextInt();
            c=kb.nextInt();
            kb.nextLine();
        }
        room[r][c] = name;
    }
    printMatrix(room);
}

public static void releaseRooms(String [][]room, int x)
{
    int r, c;
    Scanner kb = new Scanner(in);
    for(int i=0; i<x; i++)
    {   
        out.print("Enter name: ");
        String name = kb.nextLine();
        out.print("Enter the room number (row and column separated by a space) ");
        r=kb.nextInt();
        c=kb.nextInt();
        kb.nextLine();
        while(r<0 || r>room.length || c<0 || c>room[r].length)
        {
            out.print("Invalid room number. Enter another room number (row and column separated by a space) ");
            r=kb.nextInt();
            c=kb.nextInt();
            kb.nextLine();
        }
        room[r][c] = "open";

    }
    printMatrix(room);
}

publicstaticvoidmain（字符串[]args）
{
扫描仪kb=新扫描仪（英寸）；
打印（“输入行大小：”）；
int row=kb.nextInt（）；
打印（“输入列大小：”）；
int col=kb.nextInt（）；
kb.nextLine（）；
字符串[][]rooms=roomInIt（行，列）；
打印矩阵（房间）；
字符串a=“”；
对于（；；）
{
打印（“您想预订还是释放房间？键入Q退出”）；
a=kb.nextLine（）；
如果（a.同等信号（“储备”））
{
打印（“您想预订多少房间？”）；
int num=kb.nextInt（）；
预订房间（房间，数量）；
}
否则，如果（a.equalsIgnoreCase（“释放”））
{
打印（“您希望释放多少个房间？”）；
int x=kb.nextInt（）；
释放室（房间，x）；
}
否则，如果（a.equalsIgnoreCase（“Q”））；
打破
}
}
公共静态void打印矩阵（字符串[][]房间）
{
对于（int r=0；r去掉
else if（a.equalsIgnoreCase（“Q”）；

；
结束语句，这意味着
中断始终完成，而不仅仅是在满足条件时。
如果（a.equalsIgnoreCase（“Q”）；

；
结束语句，这意味着始终完成
中断
，而不仅仅是在满足条件时。
删除分号
；
：

改变

else if (a.equalsIgnoreCase("Q"));

到

删除分号
；
：

改变

else if (a.equalsIgnoreCase("Q"));

到

而不是使用

for(;;)
{
    out.print("Would you like to reserve or release a room? Type Q to exit ");
    a = kb.nextLine();

    if (a.equalsIgnoreCase("reserve"))
    {
        out.print("How many rooms would you like to reserve? ");
        int num = kb.nextInt();
        reserveRooms(rooms, num);
    }
    else if (a.equalsIgnoreCase("release"))
    {
        out.print("How many rooms would you like to release? ");
        int x = kb.nextInt();
        releaseRooms(rooms, x);
    }
    else if (a.equalsIgnoreCase("Q"));
        break;
}

为什么不使用

while (!a.equalsIgnoreCase("Q"))
{
    out.print("Would you like to reserve or release a room? Type Q to exit ");
    a = kb.nextLine();

    if (a.equalsIgnoreCase("reserve"))
    {
        out.print("How many rooms would you like to reserve? ");
        int num = kb.nextInt();
        reserveRooms(rooms, num);
    }
    else if (a.equalsIgnoreCase("release"))
    {
        out.print("How many rooms would you like to release? ");
        int x = kb.nextInt();
        releaseRooms(rooms, x);
    }
    else 
    {
        //do nothing
    }
}

而不是使用

for(;;)
{
    out.print("Would you like to reserve or release a room? Type Q to exit ");
    a = kb.nextLine();

    if (a.equalsIgnoreCase("reserve"))
    {
        out.print("How many rooms would you like to reserve? ");
        int num = kb.nextInt();
        reserveRooms(rooms, num);
    }
    else if (a.equalsIgnoreCase("release"))
    {
        out.print("How many rooms would you like to release? ");
        int x = kb.nextInt();
        releaseRooms(rooms, x);
    }
    else if (a.equalsIgnoreCase("Q"));
        break;
}

为什么不使用

while (!a.equalsIgnoreCase("Q"))
{
    out.print("Would you like to reserve or release a room? Type Q to exit ");
    a = kb.nextLine();

    if (a.equalsIgnoreCase("reserve"))
    {
        out.print("How many rooms would you like to reserve? ");
        int num = kb.nextInt();
        reserveRooms(rooms, num);
    }
    else if (a.equalsIgnoreCase("release"))
    {
        out.print("How many rooms would you like to release? ");
        int x = kb.nextInt();
        releaseRooms(rooms, x);
    }
    else 
    {
        //do nothing
    }
}

非常感谢。那些分号总是用来表示我的意思，哈哈哈。非常感谢。那些分号总是用来表示我的意思，哈哈哈。