using System;

public class Program

{   

    public void Main()

    {

        var a = new object();

        var tmp = a;

        Change(a);

        Console.WriteLine(a == tmp);

        Change2(ref a);

        Console.WriteLine(a == tmp);

    }

    public static void Change(object a)

    {

        a = new object();

    }

    public static void Change2(ref object a)

    {

        a = new object();

    }

}