Java.util.ArrayDeque.contains(Object) Method

Description

The java.util.ArrayDeque.contains(Object) returns true if this deque contains the specified element.

Declaration

Following is the declaration for java.util.ArrayDeque.contains() method

public boolean contains(Object o) 

Parameters

• o -- The object to be checked as contained in deque.

Return Value

This method returns true if this deque contains the specified element, else false.

Exception

• NA

Example

The following example shows the usage of java.util.ArrayDeque.contains() method.

package com.tutorialspoint;

import java.util.ArrayDeque;
import java.util.Deque;

public class ArrayDequeDemo {
   public static void main(String[] args) {
      
      // create an empty array deque with an initial capacity
      Deque<Integer> deque = new ArrayDeque<Integer>(8);

      // use add() method to add elements in the deque
      deque.add(20);
      deque.add(30);
      deque.add(10);
      deque.add(18);        
       
      // let us print all the elements available in deque
      for (Integer number : deque) {
         System.out.println("Number = " + number);
       }

      // deque contains element 10
      boolean retval = deque.contains(10); 
	  
      if (retval == true) {
        System.out.println("element 10 is contained in the deque");
       }
      else {
        System.out.println("element 10 is not contained in the deque");
       }
		
      // deque does not contain element 25
      boolean retval2 = deque.contains(25);
	  
      if (retval2 == true) {
        System.out.println("element 25 is contained in the deque");
       }
      else {
        System.out.println("element 25 is not contained in the deque");    
       }
   }
}      

Let us compile and run the above program, this will produce the following result:

Number = 20
Number = 30
Number = 10
Number = 18
element 10 is contained in the deque
element 25 is not contained in the deque