Java.util.ArrayDeque.removeFirst() Method

Description

The java.util.ArrayDeque.removeFirst() method retrieves and removes the first element of this deque.

Declaration

Following is the declaration for java.util.ArrayDeque.removeFirst() method

public E removeFirst()

Parameters

• NA

Return Value

This method returns the head (first element) of this deque.

Exception

• NoSuchElementException -- if this deque is empty.

Example

The following example shows the usage of java.util.ArrayDeque.removeFirst() method.

package 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(15);
      deque.add(30);
      deque.add(25);
      deque.add(40);

      // this will remove element at the first(head) postion
      int retval = deque.removeFirst();
      System.out.println("Element removed is: " + retval);

      // let us print all the elements available in deque
      for (Integer number : deque) {
         System.out.println("Number = " + number);
      }
   }
}

Let us compile and run the above program, this will produce the following result:

Number = 15
Number = 30
Number = 25
Number = 40
Element removed is: 15
Number = 30
Number = 25
Number = 40