C# | Create HashSet from another collection

A HashSet is an unordered collection of the unique elements. It comes under 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 create a HashSet from another collection by passing the collection as an argument while creating the object of HashSet.

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

Example 1:

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// C# code to Create HashSet
// from another collection
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 even numbers less than
        // equal to 10 in HashSet mySet
        for (int i = 0; i < 5; i++) {
            mySet.Add(i * 2);
        }
  
        // Creating new HashSet mySet_new from already
        // Created HashSet mySet
        HashSet<int> mySet_new = new HashSet<int>(mySet);
  
        Console.WriteLine("The elements in newly created HashSet are : ");
  
        // Displaying the elements of newly created HashSet
        foreach(int i in mySet_new)
        {
            Console.WriteLine(i);
        }
    }
}

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Output:

The elements in newly created HashSet are : 
0
2
4
6
8

Example 2:

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// C# code to Create HashSet
// from another collection
using System;
using System.Collections.Generic;
  
class GFG {
  
    // Driver code
    public static void Main()
    {
  
        // Creating a HashSet of strings
        HashSet<string> mySet = new HashSet<string>();
  
        // Inserting elements into HashSet mySet
        mySet.Add("Delhi");
        mySet.Add("Noida");
        mySet.Add("Chandigarh");
        mySet.Add("New York");
        mySet.Add("Bangalore");
  
        // Creating new HashSet mySet_new from already
        // Created HashSet mySet
        HashSet<string> mySet_new = new HashSet<string>(mySet);
  
        Console.WriteLine("The elements in newly created HashSet are : ");
  
        // Displaying the elements of newly created HashSet
        foreach(string i in mySet_new)
        {
            Console.WriteLine(i);
        }
    }
}

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Output:

The elements in newly created HashSet are : 
Delhi
Noida
Chandigarh
New York
Bangalore


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

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