Java中的 ConcurrentSkipListSet last() 方法

Java .util.concurrent.ConcurrentSkipListSet的last()方法是Java中的一个内置函数，它返回该集合中当前的最后一个（最高）元素。

句法：

public E last()

返回值：该函数返回返回此集合中当前的最后一个（最高）元素。

异常：如果此集合为空，该函数将引发 NoSuchElementException。

下面的程序说明了 ConcurrentSkipListSet.last() 方法：

方案一：

// Java program to demonstrate last()
// method of ConcurrentSkipListSet
  
import java.util.concurrent.ConcurrentSkipListSet;
  
class ConcurrentSkipListSetLastExample1 {
    public static void main(String[] args)
    {
  
        // Initializing the set
        ConcurrentSkipListSet
            set = new ConcurrentSkipListSet();
  
        // Adding elements to this set
        set.add(78);
        set.add(64);
        set.add(12);
        set.add(45);
        set.add(8);
  
        // Printing the highest element of the set
        System.out.println("The highest element of the set: "
                           + set.last());
    }
}

输出：

The highest element of the set: 78

程序 2：在 last() 中显示 NoSuchElementException 的程序。

// Java program to demonstrate last()
// method of ConcurrentSkipListSet
  
import java.util.concurrent.ConcurrentSkipListSet;
  
class ConcurrentSkipListSetLastExample1 {
    public static void main(String[] args)
    {
  
        // Initializing the set
        ConcurrentSkipListSet
            set = new ConcurrentSkipListSet();
        try {
            // Printing the highest element of the set
            System.out.println("The highest element of the set: "
                               + set.last());
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

输出：

Exception: java.util.NoSuchElementException

参考： https: Java/util/concurrent/ConcurrentSkipListSet.html#last–