java - 错误: variable digitMonth might not have been initialized

Question

我正在尝试编写一个程序，该程序需要出生年、月、日，并计算生日所在的那一天。问题是，我收到此错误消息:

错误:变量digitMonth可能尚未初始化 总计=输入年份+测试2+数字月份+输入日期； ^

我不知道如何解决它。将digitMonth设置为一个数字(例如1)使程序可以运行，但是对于公式，每个月都需要不同的数字(1代表一月，4代表二月，4代表三月，0代表四月，等等)

我已经查看了其他问题中是否存在此类错误，但尚未发现任何有用的内容。

帮忙？

import java.util.Scanner;
public class Birth{

public static void main(String[] args)
{
    Scanner scan = new Scanner(System.in);
    int inputYear, inputMonth, inputDay, digitMonth, test2, total, dayNum;

    System.out.println("Enter the last two digits of the year that you were born in");
    inputYear = scan.nextInt();
    System.out.println("Enter the month number that your were born in");
    inputMonth = scan.nextInt();
    System.out.println("Enter your birth day");
    inputDay = scan.nextInt();

    test2 = inputYear / 4;

    if (inputMonth > 0 && inputMonth < 2)
    {
        digitMonth = 1;
    }
    else if (inputMonth > 1 && inputMonth < 3)
    {
            digitMonth = 4;
    }
    else if (inputMonth > 2 && inputMonth < 4)
    {
            digitMonth = 4;
    }
    else if (inputMonth > 3 && inputMonth < 5)
    {
            digitMonth = 0;
    }
    else if (inputMonth > 4 && inputMonth < 6)
    {
            digitMonth = 2;
    }
    else if (inputMonth > 5 && inputMonth < 7)
    {
            digitMonth = 5;
    }
    else if (inputMonth > 6 && inputMonth < 8)
    {
            digitMonth = 0;
    }
    else if (inputMonth > 7 && inputMonth < 9)
    {
            digitMonth = 3;
    }
    else if (inputMonth > 8 && inputMonth < 10)
    {
            digitMonth = 6;
    }
    else if (inputMonth > 9 && inputMonth < 11)
    {
            digitMonth = 1;
    }
    else if (inputMonth > 10 && inputMonth < 12)
    {
            digitMonth = 4;
    }
    else if (inputMonth > 11 && inputMonth < 13)
    {
            digitMonth = 6;
    }
    else
        System.out.println("You fuck-up");


    total = inputYear + test2 + digitMonth + inputDay;
    dayNum = total / 7;

    if (dayNum > 0 || dayNum < 2)
    {
        System.out.println("You were born on a Sunday");
    }
    else if (dayNum > 1 || dayNum < 3)
    {
        System.out.println("You were born on a Monday");
    }
    else if (dayNum > 2 || dayNum < 4)
    {
        System.out.println("You were born on a Tuesday");
    }
    else if (dayNum > 3 || dayNum < 5)
    {
        System.out.println("You were born on a Wednesday");
    }
    else if (dayNum > 4 || dayNum < 6)
    {
        System.out.println("You were born on a Thursday");
    }
    else if (dayNum > 5 || dayNum < 7)
    {
        System.out.println("You were born on a Friday");
    }
    else if (dayNum > -1 || dayNum < 1)
    {
        System.out.println("You were born on a Saturday");
    }
}

}

Answer 1

您只能在 if 和 else if 语句中为 digitMonth 赋值，而不是在最后的 else 中赋值> 声明。
那么，如果 if 和 else if 都没有成功，而只有 else 部分成功，会发生什么呢？
的那么 digitMonth 的值是多少？

答案:无

这可能永远不会在您的代码中发生，但编译器仍然会提示它。

有两种解决方案:

1) 只需为 digitMonth 指定一个初始值即可。即int digitalMonth = 0;

2) 在最后的 else 中初始化 digitMonth。即:

else{
    //some code
    digitMonth = 0;
}

希望这有帮助