How to count unique characters in string [duplicate]

Question

Lets say we have variable myString="blabla" or mystring=998769

myString.Length; //will get you your result

myString.Count(char.IsLetter);    //if you only want the count of letters:

How to get, unique character count? I mean for "blabla" result must be 3, doe "998769" it will be 4. Is there ready to go function? any suggestions?

Answer 1

You can use LINQ:

var count = myString.Distinct().Count();

It uses a fact, that string implements IEnumerable<char>.

Without LINQ, you can do the same stuff Distinct does internally and use HashSet<char>:

var count = (new HashSet<char>(myString)).Count;