Create HashSet from another collection in C#

To create HashSet from another Collection, the code is as follows−

Example

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<int> set1 = new HashSet<int>();
      set1.Add(100);
      set1.Add(200);
      set1.Add(300);
      Console.WriteLine("HashSet created from another collection...");
      foreach(int i in set1){
         Console.WriteLine(i);
      }
      HashSet<int> set2 = new HashSet<int>(set1);
      Console.WriteLine("HashSet created from another collection...");
      foreach(int i in set2){
         Console.WriteLine(i);
      }
   }
}

Output

This will produce the following output −

HashSet created from another collection...
100
200
300
HashSet created from another collection...
100
200
300

Example

Let us now see another example −

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<string> set1 = new HashSet<string>();
      set1.Add("Jacob");
      set1.Add("Tom");
      set1.Add("Harry");
      set1.Add("Harry");
      set1.Add("Tom");
      set1.Add("Harry");
      Console.WriteLine("HashSet created from another collection...");
      foreach(string i in set1){
         Console.WriteLine(i);
      }
      HashSet<string> set2 = new HashSet<string>(set1);
      Console.WriteLine("HashSet created from another collection...");
      foreach(string i in set2){
         Console.WriteLine(i);
      }
   }
}

Output

This will produce the following output −

HashSet created from another collection...
Jacob
Tom
Harry
HashSet created from another collection...
Jacob
Tom
Harry