如何通过在java中创建时钟来解决这个问题？

Question

编写一个程序，从标准输入中读取由小时、分钟和秒组成的时间。用户还可以指定时钟格式（12 小时制，AM/PM 或 24 小时制）。确保对指示的值进行完整性检查（例如，分钟数介于 0 和 59 之间）。这是我到目前为止所拥有的：public static void main(String[] args) {    Scanner scanner = new Scanner(System.in);    System.out.print("Enter the hours: ");    int hours = scanner.nextInt();    System.out.print("Enter the minutes: ");    int minutes = scanner.nextInt();    System.out.print("Enter the seconds: ");    int seconds = scanner.nextInt();    if (seconds >= 0 && seconds <= 60) {      minutes = minutes + 1;      if (minutes >= 60) {        hours = hours + 1;        minutes = 00;        if (hours >= 24) {          hours = 00;        }      }    }    System.out.println(seconds + ":" + minutes + ":" + hours);}

Answer 1

如果您使用java.util.Calendar该类，则可以摆脱手动计算。

Calendar c = Calendar.getInstance();

c.set(Calendar.HOUR_OF_DAY, hours); //24 hour format (10PM is 22)

c.set(Calendar.MINUTE, minutes);

c.set(Calendar.SECOND, seconds);

System.out.println(c.get(Calendar.HOUR_OF_DAY)

        + ":" + c.get(Calendar.MINUTE)

        + ":" + c.get(Calendar.SECOND));

输出

Enter the hours: 20

Enter the minutes: 120

Enter the seconds: 1276

22:21:16

Answer 2

您应该阅读有关整数除法/和余数的信息 %。例如：

int seconds = 150;

System.out.println("minutes: " + seconds / 60); // minutes: 2

System.out.println("seconds: " + seconds % 60); // seconds: 30

试试这个代码以了解它是如何工作的：

int seconds = 123;

int minutes = 120;

int hours = 23;

int days = 10;

minutes += seconds / 60;

seconds %= 60;

hours += minutes / 60;

minutes %= 60;

days += hours / 24;

hours %= 24;

System.out.format("%d days, %02d:%02d:%02d hours\n", days, hours, minutes, seconds);

System.exit(0);

这将打印出所有正确的时间：

11 days, 01:02:03 hours

我将在您的代码中添加一些注释：

public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);

    System.out.print("Enter the hours: ");

    int hours = scanner.nextInt();

    System.out.print("Enter the minutes: ");

    int minutes = scanner.nextInt();

    System.out.print("Enter the seconds: ");

    int seconds = scanner.nextInt();

    if (seconds >= 0 && seconds <= 60) {

      minutes = minutes + 1; // why do you increment minutes here?

      if (minutes >= 60) {

        hours = hours + 1; // if minutes is 120, then you'd have to add 2 hours

        minutes = 00; // if minutes is 61, then you should not set minutes to 0

        if (hours >= 24) {

          hours = 00; // same here

        }

      }

    }

    System.out.println(seconds + ":" + minutes + ":" + hours);

}

Answer 3

这是到目前为止的解决方案，我想..

public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);

    System.out.print("What format 12hr or 24hr? [12,24]");

    int clockFormat = scanner.nextInt();

    System.out.print("Enter seconds: ");

    int seconds = scanner.nextInt();

    System.out.print("Enter minutes: ");

    int minutes = scanner.nextInt();

    System.out.print("Enter hours: ");

    int hours = scanner.nextInt();

    if (clockFormat == 12)

    {

      while (hours > 12 || hours < 0)

      {

        System.out.print("Enter the hours: ");

        hours = scanner.nextInt();

      }

    }

    minutes += seconds / 60;

    seconds %= 60;

    hours += minutes / 60;

    minutes %= 60;

    System.out.format("%02d:%02d:%02d", hours, minutes, seconds);

    scanner.close();

}

}