Check if a HashSet is a proper subset of the specified collection in C#

To check if a HashSet is a proper subset of the specified collection, try the following code −

Example

 Live Demo

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<int> set1 = new HashSet<int>();
      set1.Add(70);
      set1.Add(100);
      set1.Add(125);
      set1.Add(150);
      Console.WriteLine("Elements in HashSet1");
      foreach(int val in set1){
         Console.WriteLine(val);
      }
      HashSet<int> set2 = new HashSet<int>();
      set2.Add(30);
      set2.Add(60);
      set2.Add(70);
      set2.Add(80);
      set2.Add(100);
      set2.Add(125);
      set2.Add(150);
      set2.Add(200);
      Console.WriteLine("Elements in HashSet2");
      foreach(int val in set2){
         Console.WriteLine(val);
      }
      Console.WriteLine("Is set1 a proper subset of set2? "+set1.IsProperSubsetOf(set2));
   }
}

Output

This will produce the following output −

Elements in HashSet1
70
100
125
150
Elements in HashSet2
30
60
70
80
100
125
150
200
Is set1 a proper subset of set2? True

Example

Let us now see another example −

Live Demo

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<int> set1 = new HashSet<int>();
      set1.Add(10);
      set1.Add(20);
      Console.WriteLine("Elements in HashSet1");
      foreach(int val in set1){
         Console.WriteLine(val);
      }
      HashSet<int> set2 = new HashSet<int>();
      set2.Add(30);
      set2.Add(60);
      set2.Add(70);
      set2.Add(80);
      set2.Add(100);
      set2.Add(125);
      set2.Add(150);
      set2.Add(200);
      Console.WriteLine("Elements in HashSet2");
      foreach(int val in set2){
         Console.WriteLine(val);
      }
      Console.WriteLine("Is set1 a proper subset of set2? "+set1.IsProperSubsetOf(set2));
   }
}

Output

This will produce the following output −

Elements in HashSet1
10
20
Elements in HashSet2
30
60
70
80
100
125
150
200 Is set1 a proper subset of set2?False