How can I use HashSet in C# to avoid duplicates?

How can I use HashSet in C# to avoid duplicates?

You can use a HashSet in C# to store unique elements. When you add an element that already exists, it won't be added again.

Can you show me a code example?

Sure! Here's a simple example:

HashSet<int> numbers = new HashSet<int>();
numbers.Add(1);
numbers.Add(2);
numbers.Add(1); // This won't be added again

foreach (var number in numbers)
{
    Console.WriteLine(number);
}

This will output 1 and 2.

What happens if I try to add a duplicate?

If you try to add a duplicate, the HashSet will simply ignore it and not throw an error. It maintains only unique values.

Are there any performance benefits to using HashSet?

Yes, HashSet provides O(1) time complexity for add, remove, and contains operations, making it very efficient for managing collections of unique items.