Filter upper case characters in CSharp

//ww  w  .ja  va2s.  c  om
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;

class Program
{
    static void Main(string[] args)
        {
            String aString = "tHis Is a test";
            
            IEnumerable<char> query = from ch in aString where Char.IsUpper(ch) select ch;
            foreach(var c in query){
               Console.WriteLine(c);
            }

        }
}