java - Switch语句: Invalid character constant

Question

我正在尝试创建一个 switch 语句，将月份作为整数，并根据该整数，我想输出月份名称。由于某种我不知道的原因，case '10' 给了我一条无效字符常量错误消息。有谁知道为什么会发生这种情况以及我该如何解决这个问题？谢谢，代码如下:

    switch (month) {
    case '1': System.out.println("January");
    break;
    case '2': System.out.println("February");
    break;
    case '3': System.out.println("March");
    break;
    case '4': System.out.println("April");
    break;
    case '5': System.out.println("May");
    break;
    case '6': System.out.println("June");
    break;
    case '7': System.out.println("July");
    break;
    case '8': System.out.println("August");
    break;
    case '9': System.out.println("September");
    break;
    case '10': System.out.println("October");
    break;
    case '11': System.out.println("November");
    break;
    case '12': System.out.println("December");
    break;
    }

回答后:

    switch (month) {
    case "1": System.out.println("January");
    break;
    case "2": System.out.println("February");
    break;
    case "3": System.out.println("March");
    break;
    case "4": System.out.println("April");
    break;
    case "5": System.out.println("May");
    break;
    case "6": System.out.println("June");
    break;
    case "7": System.out.println("July");
    break;
    case "8": System.out.println("August");
    break;
    case "9": System.out.println("September");
    break;
    case "10": System.out.println("October");
    break;
    case "11": System.out.println("November");
    break;
    case "12": System.out.println("December");
    break;
    }

更多答案后:

    switch (month) {
    case 1: System.out.println("January");
    break;
    case 2: System.out.println("February");
    break;
    case 3: System.out.println("March");
    break;
    case 4: System.out.println("April");
    break;
    case 5: System.out.println("May");
    break;
    case 6: System.out.println("June");
    break;
    case 7: System.out.println("July");
    break;
    case 8: System.out.println("August");
    break;
    case 9: System.out.println("September");
    break;
    case 10: System.out.println("October");
    break;
    case 11: System.out.println("November");
    break;
    case 12: System.out.println("December");
    break;
    }

Answer 1

'10' 有两个字符，即 '1' 和 '0'

为什么不直接使用 int 而不是 char 作为 switch 语句变量...

int month = // ... however you get your month
switch(month) {
    case 1: // ...
    case 2: // ...
    case 3: // ...
    // ...
}