Java 日历 clear()方法及实例

Calendar类中的 clear() 方法用于设置所有的日历字段值和这个Calendar的时间值。

注意： 日历类的实现可以使用默认字段值来计算日期和时间。

语法

public final void clear()

参数： 该方法不接受任何参数。

返回值： 该方法不返回任何值。

下面的程序说明了日历类的clear()方法的工作：

例子

// Java Code to illustrate clear() Method
  
import java.util.Calendar;
  
public class CalendarClassDemo {
    public static void main(String args[])
    {
        // Creating a calendar object
        Calendar calndr = Calendar.getInstance();
  
        // Displaying the Current Date
        System.out.println("Current Date&Time: "
                           + calndr.getTime());
  
        // Clear method for undefining the values
        // of the calendar
        calndr.clear();
  
        // Displaying the final result
        System.out.println("After clear method: "
                           + calndr.getTime());
    }
}

输出:

Current Date&Time: Tue Feb 12 13:01:42 UTC 2019
After clear method: Thu Jan 01 00:00:00 UTC 1970

例2 :

// Java Code to illustrate clone() Method
  
import java.util.*;
  
public class CalendarClassDemo {
    public static void main(String args[])
    {
        // Creating a calendar object
        Calendar calndr1 = new GregorianCalendar(2018, 12, 2);
  
        // Displaying current calendar
        System.out.println("Original calendar: "
                           + calndr1.getTime());
  
        // Clear method for undefining the values
        // of the calendar
        calndr1.clear();
  
        // Displaying the final result
        System.out.println("After clear method: "
                           + calndr1.getTime());
    }
}

输出:

Original calendar: Wed Jan 02 00:00:00 UTC 2019
After clear method: Thu Jan 01 00:00:00 UTC 1970

**参考资料: **https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#clear()