Question

我无法找到如何修改扫描仪中的字符。代码应采用类似'9'的数字，并在图表中找到它的位置，将其从'o'切换为'x'。我的代码：

import java.util.Scanner;
public class a10
{
public static void main (String[] args)
{
Scanner input = new Scanner (System.in);

System.out.println("1 for first class \n2 for economy \n3 to view seating chart \n0 to exit");

//error message: Your choice must be a number between 0 and 3.
int menu = input.nextInt();

if (menu == 1) {
System.out.println("Which seat would you like (1-9): ");
int selection = input.nextInt();
//Seats in first class must be between 1 and 9.");
}
else if (menu == 2) {
System.out.println("Which seat would you like (10-30): ");
int selection = input.nextInt();
//Seats in economy class must be between 10 and 30.");
}
else if (menu == 3) {
//public static boolean[] seatChart (boolean seatNumber)
char[] seatNumber;

char[][] grid = new char[][]{{'o','o','o'},{'o','o','o'},{'o','o','o'}};

      }
    }
 }

它应该如何看待

Front
x x x
x x o
o o o
x x x
x x x
x x x
x o o
o o o
x o x
o o o
Back

Answer 1

这可能是一个解决方案：

tag__tag_type__name="Equipment"

Answer 2

首先，您可以通过条件获取该错误消息（您在评论中有）并抛出错误：

if (menu < 1 || menu > 3)
   throw new IllegalArgumentException("number not between 1 and 3");

这会杀死该程序。您还可以更改if语句的效果，只是为了打印“请再次选择”。

接下来，我认为你实际上不需要双字符数组。您可以使用for循环打印该图表：

for (int count = 0; count < seatNumber.length; count++){
   System.out.print(seatNumber[count]+" ");
   if (count % 3 == 0) System.out.println();
}

因此，如果您从左到右引用座位号，这可能是表示座位表的好方法。

接下来，在1或2的情况下读取的int selection只能通过索引访问seatNumber数组。您可以将此索引中的char修改为x，如下所示：

seatNumber[selection] = 'x';

现在，从一个全部为o的数组开始，你可以使用数组工具填充：

Arrays.fill(seatNumber, 'o');

您需要import java.util.Arrays才能在代码顶部执行此操作。如果你想避免这种情况，你可以用这样的for循环填充它：

char[] seatNumber = new char[30];
for (int count = 0; count < seatNumber.length; count++){
   seatNumber[count] = 'o';
}

此外，您可能希望在声明while(true){之后的代码周围编写一个类似Scanner的while循环。然后你可以像这样退出程序：

if (menu == 0) break;

这应该允许您填写多个席位并多次显示座位表。祝你好运！

Answer 3

循环遍历您的阵列，跟踪您所在的座位数。当该号码与所选座位匹配时，将值转换为“x”。

public char[][] takeSeat(char[][] grid, int seatNum) {
    int currentSeat = 0;
    for(int i = 0; i < grid.length; i++) {
        for(int x = 0; x < grid[i].length; x++) {
            currentSeat += 1;
            if(currentSeat == seatNum) {
                grid[i][x] = 'x';
            }
        }
        System.out.println("");
    }
    return grid;
}

另外，我注意到你在选项3中创建了你的起始座位网格。最好在代码的开头创建char [] []并在整个代码中不断更新它所以你需要做的就是在选项3显示图表。显示图表。如何显示图表的示例：

else if (menu == 3) {
    //public static boolean[] seatChart (boolean seatNumber)
    for(int i = 0; i < grid.length; i++) {
        for(int x = 0; x < grid[i].length; x++) {
            System.out.print(grid[i][x]);
        }
        System.out.println("");
    }
}

还在while循环中包装选项选项，以便您可以连续运行，直到用户选择0。

以下是您的最终代码最终应如下所示：

public static void main(String[] args) {
    Scanner input = new Scanner (System.in);
    char[][] grid = new char[][]{{'o','o','o'},{'o','o','o'},{'o','o','o'}};
    while(true) {
        System.out.println("1 for first class \n2 for economy \n3 to view seating chart \n0 to exit");

        //error message: Your choice must be a number between 0 and 3.
        int menu = input.nextInt();

        if (menu == 1) {
            System.out.println("Which seat would you like (1-9): ");
            int seat = input.nextInt();
            if(!(seat < 1 || seat > 9)) {
                grid = takeSeat(grid, seat);
            } else {
                System.out.println("Not a valid seat number");
            }
            //Seats in first class must be between 1 and 9.");
        }
        else if (menu == 2) {
            System.out.println("Which seat would you like (10-30): ");
            int seat = input.nextInt();
            if(!(seat < 10 || seat > 30)) {
                grid = takeSeat(grid, seat);
            } else {
                System.out.println("Not a valid seat number");
            }
            //Seats in economy class must be between 10 and 30.");
        }
        else if (menu == 3) {
            //public static boolean[] seatChart (boolean seatNumber)
            for(int i = 0; i < grid.length; i++) {
                for(int x = 0; x < grid[i].length; x++) {
                    System.out.print(grid[i][x]);
                }
                System.out.println("");
            }
        }
        else if (menu == 0) {
            break;
        }
        else {
            System.out.println("Invalid menu option, try again");
        }
    }
}

public static char[][] takeSeat(char[][] grid, int seatNum) {
    int currentSeat = 0;
    for(int i = 0; i < grid.length; i++) {
        for(int x = 0; x < grid[i].length; x++) {
            currentSeat += 1;
            if(currentSeat == seatNum) {
                grid[i][x] = 'x';
            }
        }
        System.out.println("");
    }
    return grid;
}

如何用扫描仪修改字符串数组？

3 个答案: