C# | Union of two HashSet

using System;
using System.Collections.Generic;

class Geeks
{

    public static void Main()
    {

         // Creating a HashSet of integers
        var s1 = new HashSet<int>();

        // Creating a HashSet of integers
        var s2 = new HashSet<int>();

        // Inserting even numbers less than
        // equal to 10 in HashSet s1
        for (int i = 0; i < 5; i++) {
            s1.Add(i * 2);
        }

        // Inserting odd numbers less than
        // equal to 10 in HashSet s2
        for (int i = 0; i < 5; i++) {
            s2.Add(i * 2 + 1);
        }
        
        // Creating a new HashSet that contains the union of both HashSets s1 & s2
        var ans = new HashSet<int>(s1);
        ans.UnionWith(s2);

        // Displaying the HashSets and their union
        Console.WriteLine("HashSet s1: " + string.Join(" ", s1));
        Console.WriteLine("HashSet s2: " + string.Join(" ", s2));
        Console.WriteLine("Union of s1 and s2: " + string.Join(", ", ans));

         // Creating and initializing HashSets of integers
        var s3 = new HashSet<int> { 0 , 3, 5, 7, 9, 10 };
        var s4 = new HashSet<int> { 1, 3, 5, 7, 9 };

        var un = new HashSet<int>(s3);
        // Using the UnionWith() method to find the union of s3 and s4
        un.UnionWith(s4);

        // Displaying the HashSets and their union
        Console.WriteLine("HashSet s3: " + string.Join(" ", s3));
        Console.WriteLine("HashSet s4: " + string.Join(" ", s4));
        Console.WriteLine("Union of s3 and s4: " + string.Join(", ", un));
    

    }
}

using System;
using System.Collections.Generic;

class Geeks
{
    public static void Main()
    {
        // Creating and initializing HashSets
        HashSet<string> s1 = 
        new HashSet<string> { "Hello", "GeeksforGeeks", "GeeksforGeeks" };

        HashSet<string> s2 = 
        new HashSet<string> { "You", "are", "the", "best" };

        // Displaying the elements of the HashSet s1
        Console.WriteLine("Elements of HashSet s1: " + String.Join(" ", s1));

        // Displaying the elements of the HashSet s2
        Console.WriteLine("Elements of HashSet s2: " + String.Join(" ", s2));

        // Creating a new HashSet that contains the union of both mySet1 and mySet2
        HashSet<string> unionSet = new HashSet<string>(s1);
        unionSet.UnionWith(s2);

        // Displaying the elements of the Union set
        Console.WriteLine("Elements of the Union set: " + String.Join(" ", unionSet));
    }
}