持续时间类isNegative()方法 (Duration Class isNegative() method)

• isNegative() method is available in java.time package.

  isNegative()方法在java.time包中可用。

• isNegative() method is used to check whether this Duration object holds the value of length < 0 (i.e. negative) or not but it excludes value 0.

  isNegative()方法用于检查此Duration对象是否保留length <0(即，负数)的值，但不包含值0。

• isNegative() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  isNegative()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• isNegative() method does not throw an exception at the time of checking negative value.

  isNegative()方法在检查负值时不会引发异常。

Syntax:

句法：

    public boolean isNegative();

Parameter(s):

参数：

• None

  没有

Return value:

返回值：

The return type of this method is boolean, it returns true when this Duration holds negative value otherwise it returns false.

此方法的返回类型为boolean ，如果Duration的值为负，则返回true，否则返回false。

Example:

例：

// Java program to demonstrate the example 
// of boolean isNegative() method of Duration
import java.time.*;
public class IsNegativeOfDuration {
public static void main(String args[]) {
// Instantiates two Duration objects
Duration du1 = Duration.ofHours(-10);
Duration du2 = Duration.parse("P1DT2H20M");
// Display du1 and du2
System.out.println("du1: " + du1);
System.out.println("du2: " + du2);
// checks whether the value
// of this Duration (du1) is negative
// or not i.e here it returns true because
// the value of du1 is negative
boolean status = du1.isNegative();
// Display status
System.out.println("du1.isNegative(): " + status);
// checks whether the value
// of this Duration (du2) is negative
// or not i.e here it returns false because
// the value of du2 is positive
status = du2.isNegative();
// Display status
System.out.println("du2.isNegative(): " + status);
}
}

Output

输出量

du1: PT-10H
du2: PT26H20M
du1.isNegative(): true
du2.isNegative(): false

翻译自: https://www.includehelp.com/java/duration-isnegative-method-with-example.aspx