C# / .NET - remove items from HashSet

In this article, we would like to show you how to remove items from HashSet in C#.

Quick solution:

HashSet<string> myHashset = new HashSet<string> { "A", "B", "C" };

myHashset.Remove("A");

Practical example

In this example, we use Remove() method to delete selected item from the myHashset.

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {

        HashSet<string> myHashset = new HashSet<string> { "A", "B", "C" };

        myHashset.Remove("A");

        foreach (string item in myHashset)
            Console.WriteLine(item);
    }
}

Output:

B
C

2. Remove all items

In this example, we use Clear() method to remove all items from myHashset.

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        HashSet<string> myHashset = new HashSet<string> { "A", "B", "C" };

        Console.WriteLine("Before:");
        foreach (string item in myHashset)
            Console.WriteLine(item);

        myHashset.Clear(); // clear HashSet

        Console.WriteLine("\nAfter:");
        foreach (string item in myHashset)
            Console.WriteLine(item);
    }
}

Output:

Before:
A
B
C

After:

References

1. HashSet<T>.Remove(T) Method (System.Collections.Generic) | Microsoft Docs