Convert an Array to a HashSet in C#

This post will discuss how to convert an array to a HashSet<T> in C#.

1. Using `HashSet<T>` Constructor

The HashSet<T> class has a Constructor that takes an IEnumerable and initializes a new instance of the HashSet<T> class with elements of an array. The following example shows how to create a new HashSet<T> from an array.

using System;

using System.Collections.Generic;

public class Example

{

public static void Main()

{

int[] numbers = { 1, 2, 3, 4, 2, 5 };

HashSet<int> set = new HashSet<int>(numbers);

Console.WriteLine(String.Join(", ", set)); // 1, 2, 3, 4, 5

}

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The following code creates an extension method that generates a HashSet<T> from an IEnumerable<T> using its constructor:

using System;

using System.Collections.Generic;

public static class Extensions

{

public static HashSet<T> ToHashSet<T>(this IEnumerable<T> collection)

{

return new HashSet<T>(collection);

}

public class Example

{

public static void Main()

{

int[] numbers = { 1, 2, 3, 4, 2, 5 };

HashSet<int> set = numbers.ToHashSet();

Console.WriteLine(String.Join(", ", set)); // 1, 2, 3, 4, 5

}

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2. Using `ToHashSet()` Method

C# provides a built-in method ToHashSet() starting with .Net Framework 4.7.2. It creates a HashSet<T> from any IEnumerable<T>, as shown below:

using System;

using System.Linq;

using System.Collections.Generic;

public class Example

{

public static void Main()

{

int[] numbers = { 1, 2, 3, 4, 2, 5 };

HashSet<int> set = numbers.ToHashSet();

Console.WriteLine(String.Join(", ", set)); // 1, 2, 3, 4, 5

}

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That’s all about converting an array to a HashSet<T> in C#.

Convert an Array to a HashSet in C#

1. Using HashSet<T> Constructor

2. Using ToHashSet() Method

1. Using `HashSet<T>` Constructor

2. Using `ToHashSet()` Method