java - 同一案例的多个开关

Question

我有这个代码:

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

好吧，这段代码 100% 完美地工作......对于 int 月。我有另一个 int (avgMonth)，它只能保存相同的值 (1-12)，我只想有相同的输出(月份)。如何将 avgMonth 添加到此代码而不必复制我的整个开关和外壳？我尝试使用逗号 (month, avgMonth) 和 &&'s (month && avgMonth) 以及 +'s (month + avgMonth) 但无济于事。

Answer 1

将整个代码块封装在一个方法中，并将avgMonth 和month 作为参数传递。像这样:

public static void monthNumToName(int month) {
    // … same as before
}

或者，您可以使用 Map 简化代码:

private static final Map<Integer, String> months;
static {
    months.put(1, "January");
    months.put(2, "February");
    months.put(3, "March");
    months.put(4, "April");
    months.put(5, "May");
    months.put(6, "June");
    months.put(7, "July");
    months.put(8, "August");
    months.put(9, "September");
    months.put(10, "October");
    months.put(11, "November");
    months.put(12, "December");
}

public static void monthNumToName(int month) {
    String name = months.get(month);
    if (name == null)
        throw new IllegalArgumentException("Invalid month number: " + month);
    System.out.print(name);
}

或者更简单，只使用一个数组，因为我们事先知道月份数字限制在 1-12 范围内:

private static final String[] months = {
    "January", "February", "March", "April", "May", "June",
    "July", "August", "September", "October", "November", "December"
};

public static void monthNumToName(int month) {
    if (month < 1 || month > 12)
        throw new IllegalArgumentException("Invalid month number: " + month);
    System.out.print(months[month-1]);
}

无论如何，当您需要打印月份名称时，请执行以下操作:

monthNumToName(month);
monthNumToName(avgMonth);