Java Deque poll() Method with Examples

by Online Tutorials Library July 22, 2022

Java Deque poll() Method

The poll() method of Java Deque Interface is used to retrieve and remove the head of the deque. On the other hand, if the deque is empty, the method may return null. The above method is equivalent to pollFirst().

Specified by:

poll in interface Queue<E>

Syntax:

Parameter:

Return:

The above method is used to return the first element of the given deque. Otherwise, the method may return a null value if the deque is empty.

Example 1

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequepollExample1 {     public static void main(String[] args) {     Deque<Float> deque = new ArrayDeque<>();      deque.offerLast(45.6f);  deque.offerLast(23f);  deque.offerLast(45.8f);  deque.offerLast(66.9f);  Float val = deque.poll();  System.out.println(“The first element is : “+val);  System.out.println(“The final deque is given as : “+deque);      }  }  

Test it Now

Output:

The first element is : 45.6  The final deque is given as : [23.0, 45.8, 66.9]

Example 2

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequepollExample2 {    public static void main(String[] args) {  Deque<String> deque = new ArrayDeque<>();  deque.offer(“Java”);  deque.offer(“is”);  deque.offer(“a”);  deque.offer(“portable”);  deque.offer(“language”);  String val = deque.poll();     System.out.println(“The first string value is : “+val);     System.out.println(“The final deque is given as : “);     for (String string : deque) {  System.out.println(string);      }    }  }  

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Output:

The first string value is : Java  The final deque is given as :   is  a  portable  language

Example 3

  import java.util.ArrayDeque;  import java.util.Deque;  public class JavaDequepollExample3 {    public static void main(String[] args) {  Deque<Integer> deque = new ArrayDeque<>();  deque.offer(34);  deque.offer(65);  deque.offer(59);  deque.offer(95);  deque.offer(68);  int val = deque.poll();     System.out.println(“The first string value is : “+val);     System.out.println(“The final deque is given as : “);    for (Integer integer : deque) {  System.out.println(integer);      }    }  }  

Test it Now

Output:

The first string value is : 34  The final deque is given as :   65  59  95  68

Next TopicJava Deque

add()addAll()addfirst()addlast()contains()descendingiterator()element()getfirst()getlast()iterator java deque java tutorial methods offer()offerfirst()offerlast()peek()peekfirst()peeklast()poll()pollfirst()polllast()

Java Deque poll() Method with Examples

Java Deque poll() Method

Specified by:

Syntax:

Parameter:

Return:

Example 1

Example 2

Example 3

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