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Java ArrayDeque removeFirst() Method with Example

ArrayDeque Class removeFirst() method: Here, we are going to learn about the removeFirst() method of ArrayDeque Class with its syntax and example.
Submitted by Preeti Jain, on January 17, 2020

ArrayDeque Class removeFirst() method

• removeFirst() method is available in java.lang package.
• removeFirst() method is used to return the first element but with removing the element from this deque.
• removeFirst() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• removeFirst() method may throw an exception at the time of removing an element from this deque.
  NoSuchElementException: This exception may throw when this deque is "blank".

Syntax:

    public T removeFirst();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of this method is T, it removes the first element with returning the element of this deque.

Example:

// Java program to demonstrate the example 
// of T removeFirst() method of ArrayDeque 

import java.util.*;

public class RemoveFirstOfArrayDeque {
    public static void main(String[] args) {
        // Creating an ArrayDeque with initial capacity of
        // storing elements
        Deque < String > d_queue = new ArrayDeque < String > (10);

        // By using add() method to add elements
        // in ArrayDeque
        d_queue.add("C");
        d_queue.add("C++");
        d_queue.add("Java");
        d_queue.add("Php");
        d_queue.add("DotNet");

        // Display Deque Elements
        System.out.println("d_queue before removeFirst(): ");
        System.out.println("ArrayDeque Elements = " + d_queue);

        System.out.println();

        // By using removeFirst() method to remove and 
        // return the first element of ArrayDeque
        String ele = d_queue.removeFirst();
        System.out.println("d_queue.removeFirst(): = " + ele);
        System.out.println();

        // Display Deque Elements
        System.out.println("d_queue after removeFirst(): ");
        System.out.println("ArrayDeque Elements = " + d_queue);
    }
}

Output

d_queue before removeFirst(): 
ArrayDeque Elements = [C, C++, Java, Php, DotNet]

d_queue.removeFirst(): = C

d_queue after removeFirst(): 
ArrayDeque Elements = [C++, Java, Php, DotNet]