C # Data structure, like a dictionary, but no value

Question

Is there any data structure in C # that looks like a dictionary, but only has a key and doesn't matter. I basically want a list of integers that I can quickly find and see if there is a specific value in the list. Of course, for my current use, the list will not cause any performance problems, but it just is not suitable for the purposes of my code.

Answer 1

Yes, it is called HashSet<T> and is available in version 3.5.NET framework. If you are using .NET version 2.0, you can use the dictionary and set the values ​​to null .

Answer 2

If 3.5 is not an option, you can do something like Dictionary <int, int> and just ignore the value. I did this in 2.0, and I try to set the value in the same way as the key.

Answer 3

If you are not targeting .NET 3.5, Power Collections (open source) also provides an implementation of Set.

Answer 4

or use a SortedList where the values ​​must be unique