Vector contains() Method in Java

The java.util.vector.contains() method is used to check whether a specific element is present in the Vector or not. So basically it is used to check if a vector contains any particular element or not. 

Syntax:

Vector.contains(Object element)

Parameters: This method takes a mandatory parameter element which is of the type of vector. This is the element that needs to be tested if it is present in the vector or not. 

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

Below programs illustrate the Java.util.Vector.contains() method: 

Program 1:

Java

// Java code to illustrate contains()
import java.util.*;

public class VectorDemo {
    public static void main(String args[])
    {
        // Creating an empty Vector
        Vector<String> vec_tor = new Vector<String>();

        // Use add() method to add elements into the Vector
        vec_tor.add("Welcome");
        vec_tor.add("To");
        vec_tor.add("Geeks");
        vec_tor.add("4");
        vec_tor.add("Geeks");

        // Displaying the Vector
        System.out.println("Vector: " + vec_tor);

        // Check for "Geeks" in the Vector
        System.out.println("Does the vector contains 'Geeks'? "
                           + vec_tor.contains("Geeks"));

        // Check for "4" in the Vector
        System.out.println("Does the Vector contains '4'? "
                           + vec_tor.contains("4"));

        // Check if the Queue contains "No"
        System.out.println("Does the Queue contains 'No'? "
                           + vec_tor.contains("No"));
    }
}

Output:

Vector: [Welcome, To, Geeks, 4, Geeks]
Does the vector contains 'Geeks'? true
Does the Vector contains '4'? true
Does the Queue contains 'No'? false

Program 2:

Java

// Java code to illustrate contains()
import java.util.*;

public class VectorDemo {
    public static void main(String args[])
    {
        // Creating an empty Vector
        Vector<Integer> vec_tor = new Vector<Integer>();

        // Use add() method to add elements into the Vector
        vec_tor.add(10);
        vec_tor.add(15);
        vec_tor.add(30);
        vec_tor.add(20);
        vec_tor.add(5);

        // Displaying the Vector
        System.out.println("Vector: " + vec_tor);

        // Check for "Geeks" in the Vector
        System.out.println("Does the vector contains 'Geeks'? "
                           + vec_tor.contains("Geeks"));

        // Check for "4" in the Vector
        System.out.println("Does the Vector contains '4'? "
                           + vec_tor.contains("4"));

        // Check if the vector contains "No"
        System.out.println("Does the Vector contains 'No'? "
                           + vec_tor.contains("No"));
    }
}

Output:

Vector: [10, 15, 30, 20, 5]
Does the vector contains 'Geeks'? false
Does the Vector contains '4'? false
Does the Vector contains 'No'? false

Time complexity: O(n), // n is the number of elements in the vector.
Auxiliary space: O(n)