Java HashSet add() Method

// Java program to demonstrates the 
// working of add() in HashSet
import java.util.*;
public class Geeks {
  
    public static void main(String[] args)
    {
        // Create HashSet
        HashSet<Integer> hs = new HashSet<Integer>();

        // Add elements to set
        hs.add(1);
        hs.add(2);
        hs.add(3);

        // Checking elements in HashSet
        System.out.println("HashSet: " + hs);
    }
}

// Java program to demonstrate add() returning false 
// when trying to add a duplicate
import java.util.HashSet;

public class Geeks {
    public static void main(String[] args)
    {
        // Create a HashSet
        HashSet<String> hs = new HashSet<>();

        // Add elements to the HashSet
        System.out.println(hs.add("Java"));
        System.out.println(hs.add("C++"));

        // Trying to add a duplicate element
        System.out.println(hs.add("Java"));

        System.out.println("HashSet: " + hs);

        // Adding C
        System.out.println(hs.add("C"));

        // Trying to add a duplicate 
        // element again
        System.out.println(hs.add("C"));

        System.out.println("HashSet: " + hs);
    }
}