Check whether an element is present in a HashSet in C#

This post will discuss how to check whether an element is present in a HashSet<T> in C#.

1. Using `Enumerable.Contains()` Method

The Enumerable.Contains() method provides a simple and straightforward way to determine whether a container contains the specified element. It returns true if the container contains an element with the specified value; false otherwise.

using System;

using System.Collections.Generic;

public class Example

{

public static void Main()

{

HashSet<int> numbers = new HashSet<int>() { 1, 2, 4, 7 };

int item = 2;

bool hasItem = numbers.Contains(item);

Console.WriteLine(hasItem); // True

}

Download Run Code

2. Using `Enumerable.Any()` Method

The LINQ’s Enumerable.Any() method returns true if any element of a container satisfies the specified condition. You can create an extension method using the Any() method that checks whether an item is present in a HashSet<T>, as shown below.

using System;

using System.Linq;

using System.Collections.Generic;

public static class Extensions

{

public static bool Contain<T>(this IEnumerable<T> numbers, T item) {

return numbers.Any(x => x.Equals(item));

}

public class Example

{

public static void Main()

{

HashSet<int> set = new HashSet<int>() { 1, 2, 4, 7 };

int item = 2;

bool hasItem = set.Contain(item);

Console.WriteLine(hasItem); // True

}

Download Run Code

That’s all about checking whether an element is present in a HashSet<T> in C#.

Check whether an element is present in a HashSet in C#

1. Using Enumerable.Contains() Method

2. Using Enumerable.Any() Method

Share this:

1. Using `Enumerable.Contains()` Method

2. Using `Enumerable.Any()` Method