java.util.concurrent.ConcurrentSkipListSet的first()方法是Java中的内置函数,它返回当前该集合中的第一个(最低)元素。
用法:
ConcurrentSkipListSet.first()
返回值:该函数返回此集合中当前的第一个(最低)元素。
异常:如果此集合为空,则该函数将引发NoSuchElementException。
以下示例程序旨在说明ConcurrentSkipListSet.first()方法:
示例1:
// Java Program Demonstrate first()
// method of ConcurrentSkipListSet
import java.util.concurrent.ConcurrentSkipListSet;
class ConcurrentSkipListSetFirstExample1 {
public static void main(String[] args)
{
// Initializing the set
ConcurrentSkipListSet<Integer>
set = new ConcurrentSkipListSet<Integer>();
// Adding elements to first set
set.add(10);
set.add(35);
set.add(20);
set.add(25);
System.out.println("The lowest element in the set: "
+ set.first());
}
}
输出:
The lowest element in the set: 10
示例2:程序以在first()中显示NoSuchElementException。
// Java Program Demonstrate first()
// method of ConcurrentSkipListSet
import java.util.concurrent.ConcurrentSkipListSet;
class ConcurrentSkipListSetFirstExample2 {
public static void main(String[] args) throws InterruptedException
{
// Initializing the set
ConcurrentSkipListSet<Integer>
set = new ConcurrentSkipListSet<Integer>();
try {
System.out.println("The lowest element in the set: " +
set.first());
}
catch (Exception e) {
System.out.println("Exception :" + e);
}
}
}
输出:
Exception :java.util.NoSuchElementException
参考: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListSet.html#first–
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注:本文由纯净天空筛选整理自rupesh_rao大神的英文原创作品 ConcurrentSkipListSet first() method in Java。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。