Best collection to use with type Double as key

Question

I have this object:

Public Cactus{
    Public Double key;
    Public String value;
}

I have about ~100 Cactus, which all have

Answer 1

Using a double as a key in a dictionary is generally a really bad idea. You will run into all sorts of problems with representation errors where you think you stored 0.1 in the dictionary but actually you stored something very close to but not quite equal to 0.1.

I'd suggest using another type (string?) if you need exact matches.

If you don't want exact matches but just finding the closest value, consider something like a SortedList instead.