How to find Intersection of Two Sets in C# - Step by Step Examples

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How to find Intersection of Two Sets in C# ?

Answer

In C#, you can use the LINQ library to find the intersection of two sets.

✐ Examples

1 Find Intersection of Two Sets using LINQ

In this example,

We import the System.Linq namespace to access LINQ functionality.
We define two sets, set1 and set2, using the HashSet class.
We use LINQ's Intersect method to find the intersection of set1 and set2.
The result of the intersection operation is stored in intersection.
We iterate through the intersection set and print each element to display the intersection of the two sets.

C# Program

using System;
using System.Collections.Generic;
using System.Linq;

namespace SetIntersectionExample
{
    class Program
    {
        static void Main(string[] args)
        {
            HashSet<int> set1 = new HashSet<int> { 1, 2, 3, 4 };
            HashSet<int> set2 = new HashSet<int> { 3, 4, 5, 6 };

            var intersection = set1.Intersect(set2);

            Console.WriteLine("Intersection of set1 and set2:");
            foreach (var item in intersection)
            {
                Console.WriteLine(item);
            }
        }
    }
}

Output

Intersection of set1 and set2:
3
4

2 Find Intersection of Two Sets using Custom Implementation

In this example,

We create two sets, set1 and set2, using the HashSet class and add elements to them.
We define a custom method named FindIntersection that takes two HashSet objects as input parameters.
In the FindIntersection method, we iterate through set1 and check if each element is present in set2.
If an element is found in both sets, it is added to a new HashSet named intersection.
We return the intersection set containing the common elements.

C# Program

using System;
using System.Collections.Generic;

namespace SetIntersectionExample
{
    class Program
    {
        static void Main(string[] args)
        {
            HashSet<int> set1 = new HashSet<int> { 1, 2, 3, 4 };
            HashSet<int> set2 = new HashSet<int> { 3, 4, 5, 6 };

            var intersection = FindIntersection(set1, set2);

            Console.WriteLine("Intersection of set1 and set2:");
            foreach (var item in intersection)
            {
                Console.WriteLine(item);
            }
        }

        static HashSet<int> FindIntersection(HashSet<int> set1, HashSet<int> set2)
        {
            HashSet<int> intersection = new HashSet<int>();
            foreach (var item in set1)
            {
                if (set2.Contains(item))
                {
                    intersection.Add(item);
                }
            }
            return intersection;
        }
    }
}

Output

Intersection of set1 and set2:
3
4

Summary

In this tutorial, we learned How to find Intersection of Two Sets in C# language with well detailed examples.

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