如何将比较if语句转换为switch case语句？[副本]

Question

我是java编程新手，很难弄清楚这一点。

这是我的代码：

boolean running = true;
   PANTS:
while (running) {
    int waistMeasure = in.nextInt();

    if (waistMeasure >= 26 && waistMeasure < 28){
        System.out.println("You are a Small.");
        break;
    }
    if (waistMeasure >= 28 && waistMeasure < 30){
        System.out.println("You are a Medium.");
        break;
    }
    if (waistMeasure >= 30 && waistMeasure <= 34){
        System.out.println("You are a Large.");
        break;
    }

    else {
        System.out.println("Invalid input");
    }
}

有没有办法将其转换为switch-case语句？

Answer 1

你是说这样的事吗？

请注意，您必须使用break语句的PANTS标签退出循环，否则它们将从开关中断，并将继续循环。

PANTS: for (;;) {
    int waistMeasure = in.nextInt();
    switch (waistMeasure) {
        case 26:
        case 27:
            System.out.println("You are a Small.");
            break PANTS;
        case 28:
        case 29:
            System.out.println("You are a Medium.");
            break PANTS;
        case 30:
        case 31:
        case 32:
        case 33:
        case 34:
            System.out.println("You are a Large.");
            break PANTS;
        default:
            System.out.println("Invalid input");
    }
}

Answer 2

switch (waistMeasure) {
    case 26:
    case 27:
        System.out.println("You are a Small.");
        break PANTS;
    case 28:
    case 29:
        System.out.println("You are a Medium.");
        break PANTS;
    case 30:
    case 31:
    case 32:
    case 33:
    case 34:
        System.out.println("You are a Large.");
        break PANTS;
    default
        System.out.println("Invalid input");
}

Answer 3

是的，有–但您必须为每个值创建一个大小写（如下所示）。不能用单个大小写来表示一系列值。因此，如果您想要可读和可维护的代码，您应该坚持使用if。

switch (waistMeasure) {
case 26:
case 27:
    System.out.println("You are a Small.");
    running = false;
    break;
case 28:
case 29:
// ....
}