How to get distinct characters?

Question

I have a code like

string code = \"AABBDDCCRRFF\";

In this code, I want to retrieve only distinct characters

The Output should be l

Answer 1

Here's an approach with grouping by characters...

var code="AABBDDCCRRFF";
var unique = string.Concat(text.GroupBy(a => a).Select(a => a.Key));