Java 中的 concurrentlinkedequepollast()方法

原文:https://www . geeksforgeeks . org/concurrentlinkedeque-poll last-method-in-Java/

java . util . concurrentlinkedequest . pollast()是 Java 中的一个内置方法,它检索这个 deque 的最后一个元素并将其移除。如果目的地为空,则该方法返回空值

语法:

Conn_Linked_Deque.pollLast()

参数:函数不接受参数。

返回值:函数返回这个的最后一个元素。如果这个德格为空,则该功能返回

下面的程序说明了 pollFirst()方法的使用:

程序 1: 该程序涉及带有整数元素的德格。

/* Java Program Demonstrate pollLast() 
 method of ConcurrentLinkedDeque   */

import java.util.concurrent.*;

class ConcurrentLinkedDequeDemo {
    public static void main(String[] args)
    {
        ConcurrentLinkedDeque<Integer> cld = 
                     new ConcurrentLinkedDeque<Integer>();

        cld.addFirst(12);
        cld.addFirst(70);
        cld.addFirst(1009);
        cld.addFirst(475);

        // Displaying the existing LinkedDeque
        System.out.println("Elements in"
                           + "the LinkedDeque: " + cld);

        // Display and remove the Last element
        System.out.println("Element removed : "
                           + cld.pollLast());

        // Displaying the elements
        System.out.println("Elements in"
                           + "the LinkedDeque: " + cld);
    }
}

输出:

Elements inthe LinkedDeque: [475, 1009, 70, 12]
Element removed : 12
Elements inthe LinkedDeque: [475, 1009, 70]

节目 2: 这个节目涉及到带有元素的德格。

/* Java Program Demonstrate pollLast() 
 method of ConcurrentLinkedDeque   */

import java.util.concurrent.*;

class ConcurrentLinkedDequeDemo {
    public static void main(String[] args)
    {
        ConcurrentLinkedDeque<String> cld = 
                       new ConcurrentLinkedDeque<String>();

        cld.addFirst("GFG");
        cld.addFirst("Geeks");
        cld.addFirst("Gfg");
        cld.addFirst("Geeks");

        // Displaying the existing LinkedDeque
        System.out.println("Elements in"
                           + "the LinkedDeque: " + cld);

        // Display and remove the Last element
        System.out.println("Element removed : "
                           + cld.pollLast());

        // Displaying the elements
        System.out.println("Elements in"
                           + "the LinkedDeque: " + cld);
    }
}

输出:

Elements inthe LinkedDeque: [Geeks, Gfg, Geeks, GFG]
Element removed : GFG
Elements inthe LinkedDeque: [Geeks, Gfg, Geeks]

参考:https://docs . Oracle . com/javase/8/docs/API/Java/util/concurrentlinkedeque . html # pollast()