Java.util.ArrayDeque.pollFirst() Method
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Description
The java.util.ArrayDeque.pollFirst() method retrieves and removes the first element of this deque.Returns null if this deque is empty.
Declaration
Following is the declaration for java.util.ArrayDeque.pollFirst() method
public E pollFirst()
Parameters
NA
Return Value
This method returns the head of this deque, or null if this deque is empty.
Exception
NA
Example
The following example shows the usage of java.util.ArrayDeque.pollFirst() method.
Live Demopackage com.tutorialspoint; import java.util.ArrayDeque; import java.util.Deque; public class ArrayDequeDemo { public static void main(String[] args) { // create an empty array deque with an initial capacity Deque<Integer> deque = new ArrayDeque<Integer>(8); // use add() method to add elements in the deque deque.add(25); deque.add(30); deque.add(20); deque.add(18); // printing all the elements available in deque for (Integer number : deque) { System.out.println("Number = " + number); } int retval = deque.pollFirst(); System.out.println("Element removed is " + retval); // printing all the elements available in deque after using pollFirst() for (Integer number : deque) { System.out.println("Number = " + number); } } }
Let us compile and run the above program, this will produce the following result −
Number = 25 Number = 30 Number = 20 Number = 18 Element removed is 25 Number = 30 Number = 20 Number = 18
java_util_arraydeque.htm
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