Check if a HashSet contains the specified element in C#

To check if a HashSet contains the specified element, the code is as follows −

Example

 Live Demo

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<int> set1 = new HashSet<int>();
      set1.Add(25);
      set1.Add(50);
      set1.Add(75);
      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(100);
      set2.Add(150);
      set2.Add(200);
      set2.Add(250);
      Console.WriteLine("Elements in HashSet2");
      foreach(int val in set2){
         Console.WriteLine(val);
      }
      Console.WriteLine("Do they share common elements? "+set1.Overlaps(set2));
      Console.WriteLine("Does HashSet1 has element 60? "+set1.Contains(60));
      Console.WriteLine("Does HashSet2 has element 60? "+set2.Contains(60));
   }
}

Output

This will produce the following output −

Elements in HashSet1
25
50
75
100
125
150
Elements in HashSet2
30
60
100
150
200
250
Do they share common elements? True
Does HashSet1 has element 60? False
Does HashSet2 has element 60? True

Example

 Live Demo

Let us now see another example;
using System;
using System.Collections.Generic;
public class Demo {
   public static void Main(){
      HashSet<string> hashSet = new HashSet<string>();
      hashSet.Add("Tim");
      hashSet.Add("Jack");
      hashSet.Add("Matt");
      hashSet.Add("Steve");
      hashSet.Add("David");
      hashSet.Add("Kane");
      hashSet.Add("Gary");
      Console.WriteLine("Elements in HashSet");
      foreach(string val in hashSet){
         Console.WriteLine(val);
      }
      if (hashSet.Contains("Matt"))
         Console.WriteLine("The element Matt is in the HashSet");
      else
         Console.WriteLine("The element Matt is not in the HashSet");
   }
}

Output

This will produce the following output −

Elements in HashSet
Tim
Jack
Matt
Steve
David
Kane
Gary
The element Matt is in the HashSet