ArrayDeque removeFirstOccurrence() Method in Java

The java.util.ArrayDeque.removeFirstOccurrence(Object) method in Java is used to remove the first occurrence of a specific element from this deque. If the element is present only once, then that element is removed and true is returned. If no such element is removed then false is returned.

Syntax:

Array_Deque.removeFirstOccurrence(Object O)

Parameters: The method takes one parameter O of ArrayDeque type and refers to the element whose first occurrence is to be removed.

Return Value: This method returns true if the element is present in the map else it returns false.

Below programs illustrate the Java.util.ArrayDeque.removeFirstOccurrence() method:

Program 1:

// Java code to illustrate removeFirstOccurrence()
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 removeFirstOccurrence() method
        de_que.removeFirstOccurrence("Geeks");
        de_que.removeFirstOccurrence("For");

        // 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: [Welcome, To, Geeks]

Program 2:

// Java code to illustrate removeFirstOccurrence()
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(10);
        de_que.add(30);
        de_que.add(10);
        de_que.add(30);

        // Displaying the ArrayDeque
        System.out.println("Initial ArrayDeque: " + de_que);

        // Removing elements using removeFirstOccurrence() method
        de_que.removeFirstOccurrence(30);
        de_que.removeFirstOccurrence(5);

        // Displaying the ArrayDeque after removal
        System.out.println("ArrayDeque after removing "
                           + "elements: " + de_que);
    }
}

Output:

Initial ArrayDeque: [10, 10, 30, 10, 30]
ArrayDeque after removing elements: [10, 10, 10, 30]