Java ArrayDeque - removeFirst() Method

The java.util.ArrayDeque.removeFirst() method is used to remove and return the first element of the deque. Every removal of element results into reducing the deque size by one unless the deque is empty.

Syntax

public E removeFirst()

Here, E is the type of element maintained by the container.

Parameters

No parameter is required.

Return Value

Returns the first element of the deque.

Exception

Throws NoSuchElementException, if the deque is empty.

Example:

In the example below, the java.util.ArrayDeque.removeFirst() method is used to remove and return the first element of the given deque.

import java.util.*;

public class MyClass {
  public static void main(String[] args) {
    //creating an ArrayDeque
    ArrayDeque<Integer> MyDeque = new ArrayDeque<Integer>();

    //populating the ArrayDeque 
    MyDeque.add(10);
    MyDeque.add(20);
    MyDeque.add(30);

    //printing the ArrayDeque
    System.out.print("MyDeque contains: ");
    while(MyDeque.size() != 0) {
      System.out.print(MyDeque.removeFirst()+ " ");
   }
  }
}

The output of the above code will be:

MyDeque contains: 10 20 30