using System;

public class Program

{

    static void HocForeach()

    {

        string str = "abcde";

        string newCh = "";

        string ch = "";

        foreach(char c in str)

        {

            ch = char.ToUpper(c).ToString();

            newCh += ch;

        }

        Console.WriteLine("Kết quả chuỗi: {0}",newCh);

        Console.ReadLine();

    }

    public static void Main()

    {

        HocForeach();

    }

}