使用 java - 在 switch 中使用 if else 语句？

Question

我对 Java 还很陌生，一般来说编码。在我的 class 中，我们需要用户输入月份 (1-12) 和日期 (1-30)，然后我们在设定的日期（6 月 15 日至 9 月 30 日）确定是否是季风季节.我试图在 switch 中使用 if else 语句来说明 6 月 15 日之前的任何时候都不是季风季节，但我的代码一直显示 if 和 else 语句。欢迎任何帮助，谢谢！

import java.util.*;

public class Monsoon

 {  public static void main (String[]args)
    {
    Scanner kb = new Scanner (System.in);



    // Prompt the user to enter month & Day
    System.out.print("Please enter a month(1-12) and day (1-31): " );
    int month = kb.nextInt();
    int day = kb.nextInt();


    // using a switch statement to show months
    switch (month){
        case 1:
            System.out.println("is NOT monsoon season");
            break;
        case 2:
            System.out.println("is NOT monsoon season");
            break;
        case 3:
        System.out.println("is NOT monsoon season");
            break;
        case 4:
            System.out.println("is NOT monsoon season");
            break;
        case 5:
            System.out.println("is NOT monsoon season");
            break;
        case 6:
            System.out.println("“is monsoon season");

            // use if else statement so user knows that before june 15 is not monsoon season
        if (day>=15)
            System.out.print("it is monsoon season");
        else
            System.out.print("it is not monsoon season");


            break;
        case 7:
            System.out.println("“is monsoon season");
            break;
        case 8:
            System.out.println("“is monsoon season");
            break;
        case 9:
            System.out.println("“is monsoon season");
            break;
        case 10:
            System.out.println("is NOT monsoon season");
            break;
        case 11:
            System.out.println("is NOT monsoon season");
            break;
        case 12:
            System.out.println("is NOT monsoon season");
            break;

        default: System.out.println("not valid");
        break;

    }

}

}

Answer 1

重复不好。你可以这样做，利用 switch-case 的 fall-through 特性：

boolean isMonsoon;

switch (month) {
    case 7:
    case 8:
    case 9:
        isMonsoon = true;
        break;

    case 1:
    case 2:
    case 3:
    case 4:
    case 5:
    case 10:
    case 11:
    case 12:
        isMonsoon = false;
        break;

    case 6:
        // use if else statement so user knows that before june 15 is not monsoon season
        if (day >= 15)
            isMonsoon = true;
        else
            isMonsoon = false;
        break;

    default:
        System.out.println("not valid");
        break;
}

if (isMonsoon)
    System.out.println("is monsoon season");
else
    System.out.println("is NOT monsoon season");

或者，由于季风季节是范围，使用比较运算符可能比 switch-case 更合适：

if ((month >= 7 && month < 10) || (month == 6 && day >= 15))
    System.out.println("is monsoon season");
else
    System.out.println("is NOT monsoon season");

使用 java - 在 switch 中使用 if else 语句？

Using java - using if else statement in a switch?

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