C# | Number of elements in HashSet

A HashSet is an unordered collection of the unique elements. It is found in System.Collections.Generic namespace. It is used in a situation where we want to prevent duplicates from being inserted in the collection. As far as performance is concerned, it is better in comparison to the list. You can use HashSet.Count Property to count the number of elements in a HashSet.

Syntax:

mySet.Count;

Here mySet is the HashSet



Below given are some examples to understand the implementation in a better way:

Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# code to get the number of
// elements that are contained in HashSet
using System;
using System.Collections.Generic;
  
class GFG {
  
    // Driver code
    public static void Main()
    {
  
        // Creating a HashSet of integers
        HashSet<int> mySet = new HashSet<int>();
  
        // Inserting elements in HashSet
        for (int i = 0; i < 5; i++) {
            mySet.Add(i * 2);
        }
  
        // To get the number of
        // elements that are contained in HashSet
        Console.WriteLine(mySet.Count);
    }
}

chevron_right


Output:

5

Example 2:

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# code to get the number of
// elements that are contained in HashSet
using System;
using System.Collections.Generic;
  
class GFG {
  
    // Driver code
    public static void Main()
    {
  
        // Creating a HashSet of integers
        HashSet<int> mySet = new HashSet<int>();
  
        // To get the number of
        // elements that are contained in HashSet.
        // Note that, here the HashSet is empty
        Console.WriteLine(mySet.Count);
    }
}

chevron_right


Output:

0

Reference:



My Personal Notes arrow_drop_up

In love with a semicolon because sometimes i miss it so badly)

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.