Java TreeSet pollLast()用法及代码示例

Java.util.concurrent.TreeSet的pollLast()方法是Java中的内置函数，该函数返回检索并删除最后一个(最高)元素，如果此集为空，则返回null。

用法:

public E pollLast()

返回值：该函数返回以检索并删除最后一个(最高)元素，如果此集合为空，则返回null。

以下示例程序旨在说明TreeSet.pollLast()方法：

示例1:

// Java program to demonstrate pollLast() 
// method of TreeSet 
  
import java.util.*; 
  
class TreeSetpollLastExample1 { 
    public static void main(String[] args) 
    { 
        // Creating a set object 
        TreeSet<Integer> set 
            = new TreeSet<Integer>(); 
  
        // Adding elements to this set 
        for (int i = 10; i <= 50; i += 10) 
            set.add(i); 
  
        // Printing the content of the set 
        System.out.println("Contents of the set: " + set); 
  
        // Retrieving and removing Last element of the set 
        System.out.println("The Last element of the set: "
                           + set.pollLast()); 
  
        // Printing the content of the set after pollLast() 
        System.out.println("Contents of the set after pollLast: "
                           + set); 
    } 
}

输出：

Contents of the set: [10, 20, 30, 40, 50]
The Last element of the set: 50
Contents of the set after pollLast: [10, 20, 30, 40]

示例2:

// Java program to demonstrate pollLast() 
// method of TreeSet 
  
import java.util.*; 
  
class TreeSetpollLastExample2 { 
    public static void main(String[] args) 
    { 
        // Creating a set object 
        TreeSet<Integer> set 
            = new TreeSet<Integer>(); 
  
        // Printing the content of the set 
        System.out.println("Contents of the set: "
                           + set); 
  
        // Retrieving and removing Last element of the set 
        System.out.println("The Last element of the set: "
                           + set.pollLast()); 
    } 
}

输出：

Contents of the set: []
The Last element of the set: null

相关用法

注：本文由纯净天空筛选整理自VatsalChoudhary大神的英文原创作品 TreeSet pollLast() method in Java with Example。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。