The Java.util.ArrayDeque.removeFirst() method is used to remove the first element of the Deque.
Syntax:
Array_Deque.removeFirst()
Parameters: The method does not take any parameters.
Return Value: This method returns the first element of the Deque after removing it.
Exceptions: The method throws NoSuchElementException is thrown if the deque is empty.
Below programs illustrate the Java.util.ArrayDeque.removeFirst() method:
Program 1:
// Java code to illustrate removeFirst() import java.util.*;
public class ArrayDequeDemo {
public static void main(String args[])
{
// Creating an empty ArrayDeque
Deque<String> de_que = new ArrayDeque<String>();
// Use add() method to add elements into the Deque
de_que.add( "Welcome" );
de_que.add( "To" );
de_que.add( "Geeks" );
de_que.add( "For" );
de_que.add( "Geeks" );
// Displaying the ArrayDeque
System.out.println( "Initial ArrayDeque: " + de_que);
// Removing elements using removeFirst() method
de_que.removeFirst();
de_que.removeFirst();
de_que.removeFirst();
// Displaying the ArrayDeque after removal
System.out.println( "ArrayDeque after removing "
+ "elements: " + de_que);
}
} |
Output:
Initial ArrayDeque: [Welcome, To, Geeks, For, Geeks] ArrayDeque after removing elements: [For, Geeks]
Program 2:
// Java code to illustrate removeFirst() import java.util.*;
public class ArrayDequeDemo {
public static void main(String args[])
{
// Creating an empty ArrayDeque
Deque<Integer> de_que = new ArrayDeque<Integer>();
// Use add() method to add elements into the Deque
de_que.add( 10 );
de_que.add( 15 );
de_que.add( 30 );
de_que.add( 20 );
de_que.add( 5 );
// Displaying the ArrayDeque
System.out.println( "Initial ArrayDeque: " + de_que);
// Removing elements using removeFirst() method
de_que.removeFirst();
de_que.removeFirst();
// Displaying the ArrayDeque after removal
System.out.println( "ArrayDeque after removing "
+ "elements: " + de_que);
}
} |
Output:
Initial ArrayDeque: [10, 15, 30, 20, 5] ArrayDeque after removing elements: [30, 20, 5]