Java中LinkedBlockingDeque的element()方法

LinkedBlockingDeque 类的 element() 方法，返回容器前端的元素，并不删除容器中的元素。该方法返回由此双端队列表示的队列的头部。

语法:

public void element()

参数: 此方法不接受任何参数。

返回值: 返回由此双端队列表示的队列的头部。

下面程序演示了LinkedBlockingDeque的element()方法：

程序 1:

// Java程序演示LinkedBlockingDeque的element()方法
 
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
 
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
 
        // 创建LinkedBlockingDeque对象
        LinkedBlockingDeque<Integer> LBD
            = new LinkedBlockingDeque<Integer>();
 
        // 将数字添加到LinkedBlockingDeque末尾
        LBD.add(10);
        LBD.add(20);
        LBD.add(30);
        LBD.add(40);
 
        // 在删除前打印队列
        System.out.println("Linked Blocking Deque: " + LBD);
 
        System.out.println("Linked Blocking Deque前端元素: " +
                                                     LBD.element());
    }
}

输出:

Linked Blocking Deque: [10, 20, 30, 40]
Linked Blocking Deque前端元素: 10

程序 2:

// Java程序演示LinkedBlockingDeque的element()方法
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
 
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
 
        // 创建LinkedBlockingDeque对象
        LinkedBlockingDeque<String> LBD
            = new LinkedBlockingDeque<String>();
 
        // 将数字添加到LinkedBlockingDeque末尾
        LBD.add("ab");
        LBD.add("cd");
        LBD.add("fg");
        LBD.add("xz");
 
        // 在删除前打印队列
        System.out.println("Linked Blocking Deque: " + LBD);
 
        System.out.println("Linked Blocking Deque前端元素: " +
                                                     LBD.element());
    }
}

输出:

Linked Blocking Deque: [ab, cd, fg, xz]
Linked Blocking Deque前端元素: ab

参考: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/LinkedBlockingDeque.html#element()