ArrayDeque contains() Method in Java

Last Updated : 10 Dec, 2018

The Java.util.ArrayDeque.contains() method in Java is used to check or verify whether a specific element is present in the Deque or not.

Syntax:

Array_Deque.contains(Object element)

Parameters: The parameter element is of the type of ArrayDeque. This is the element that needs to be tested if it is present in the deque or not.

Return Value: The method returns True if the element is present in the deque otherwise it returns False.

Below programs illustrate the Java.util.ArrayDeque.contains() method:
Program 1:

// Java code to illustrate contains()
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 Queue
        de_que.add("Welcome");
        de_que.add("To");
        de_que.add("Geeks");
        de_que.add("4");
        de_que.add("Geeks");
  
        // Displaying the ArrayDeque
        System.out.println("ArrayDeque: " + de_que);
  
        // Check for "Geeks" in the deque
        System.out.println("Does the deque contains 'Geeks'? "
                           + de_que.contains("Geeks"));
  
        // Check for "4" in the deque
        System.out.println("Does the deque contains '4'? "
                           + de_que.contains("4"));
  
        // Check if the deque contains "No"
        System.out.println("Does the deque contains 'No'? "
                           + de_que.contains("No"));
    }
}

Output:

ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
Does the deque contains 'Geeks'? true
Does the deque contains '4'? true
Does the deque contains 'No'? false

Program 2:

// Java code to illustrate contains()
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 Queue
        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("ArrayDeque: " + de_que);
  
        // Check for '15' in the Deque
        System.out.println("Does the Deque contains '15'? "
                           + de_que.contains(15));
  
        // Check for '2' in the Deque
        System.out.println("Does the Deque contains '2'? "
                           + de_que.contains(2));
  
        // Check if the Deque contains '10'
        System.out.println("Does the Deque contains '10'? "
                           + de_que.contains(10));
    }
}

Output:

ArrayDeque: [10, 15, 30, 20, 5]
Does the Deque contains '15'? true
Does the Deque contains '2'? false
Does the Deque contains '10'? true

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