using System;

public class TestClass

    {

        public string TestString { get; set; }

    }

​

​

​

public static class Program

{

    public static void DoSomething(TestClass obj)

        {

            obj.TestString = "Gigel";

        }

​

        public static void Main(string[] args)

        {

            TestClass obj = new TestClass();

            obj.TestString = "Nicu";

​

            DoSomething(obj);

​

            Console.WriteLine(obj.TestString);

        }

​

}