java - 如何根据用户输入计算一年中的剩余天数

Question

我有一个作业问题，内容如下:编写一个程序，提示用户输入日期(以三个数字的形式:年月日)，并使用getDays()方法来帮助计算从给定日期到新年的天数。以下是一些示例运行:

• 请输入日期:2018 年 12 月 20 日
  距离新年还有 12 天。
• 请输入日期:1980 年 1 月 5 日
  距离新年还有 362 天。

这是我到目前为止的代码:

public class Lab9Question4 {

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Please enter a date: ");
    int year = input.nextInt();
    int month = input.nextInt();
    int days = input.nextInt();
    input.close();
    long diff = getDays(year, month) - days;
    long days_diff = diff + 1;                                              
    System.out.println("There are " + days_diff + " day(s) until New Year.");
}

public static int getDays(int year, int month) {
    int number_Of_DaysInMonth = 0;
    
    switch (month) {
    case 1:
        number_Of_DaysInMonth = 31;
        break;
    case 2:
        if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))) {
            number_Of_DaysInMonth = 29;
        } else {
            number_Of_DaysInMonth = 28;
        }
        break;
    case 3:
        number_Of_DaysInMonth = 31;
        break;
    case 4:
        number_Of_DaysInMonth = 30;
        break;
    case 5:
        number_Of_DaysInMonth = 31;
        break;
    case 6:
        number_Of_DaysInMonth = 30;
        break;
    case 7:
        number_Of_DaysInMonth = 31;
        break;
    case 8:
        number_Of_DaysInMonth = 31;
        break;
    case 9:
        number_Of_DaysInMonth = 30;
        break;
    case 10:
        number_Of_DaysInMonth = 31;
        break;
    case 11:
        number_Of_DaysInMonth = 30;
        break;
    case 12:
        number_Of_DaysInMonth = 31;

    }
    return number_Of_DaysInMonth;
    }
}

我知道我需要在某处使用循环，以便获取用户输入后的剩余天数，并将它们添加到日期差中以获得直到新的一年的天数，但我不确定在哪里插入循环以及其中应该包含的内容。如有任何帮助，我们将不胜感激:)

更新:感谢所有快速回复的人，此代码现在可以完美运行!新代码如下，供将来可能需要它的其他人使用:

public class Lab9Question4 {

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Please enter a date: ");
    int year = input.nextInt();
    int month = input.nextInt();
    int days = input.nextInt();
    input.close();
    int remainingDays = getDays(month, year) - days + 1;
    for (int currentMonth = month; currentMonth <= 12; currentMonth++) {
        remainingDays += getDays(year, currentMonth);
    }

    System.out.println("There are " + remainingDays + " day(s) until New Year.");
}

public static int getDays(int year, int month) {
    int number_Of_DaysInMonth = 0;

    switch (month) {
    case 1:
        number_Of_DaysInMonth = 31;
        break;
    case 2:
        if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))) {
            number_Of_DaysInMonth = 29;
        } else {
            number_Of_DaysInMonth = 28;
        }
        break;
    case 3:
        number_Of_DaysInMonth = 31;
        break;
    case 4:
        number_Of_DaysInMonth = 30;
        break;
    case 5:
        number_Of_DaysInMonth = 31;
        break;
    case 6:
        number_Of_DaysInMonth = 30;
        break;
    case 7:
        number_Of_DaysInMonth = 31;
        break;
    case 8:
        number_Of_DaysInMonth = 31;
        break;
    case 9:
        number_Of_DaysInMonth = 30;
        break;
    case 10:
        number_Of_DaysInMonth = 31;
        break;
    case 11:
        number_Of_DaysInMonth = 30;
        break;
    case 12:
        number_Of_DaysInMonth = 31;

    }
    return number_Of_DaysInMonth;
}

}

Answer 1

我建议你查看LocalDate的文档类(class)。

.until() 方法应该适合您的情况。您不必手动计算。