using System;

public class Program

{

    public static void Main()

    {

        var sample1 = new Sample(1);

        Console.WriteLine("Created {0}", sample1);

        WithoutRef(sample1);

        Console.WriteLine("Resulting {0}", sample1);

        Console.WriteLine();

        Console.WriteLine("NOW USING REF");

        var sample2 = new Sample(1);

        Console.WriteLine("Created {0}", sample2);

        WithRef(ref sample2);

        Console.WriteLine("Resulting {0}", sample2);

    }

    public static void WithoutRef(Sample sample)

    {

        Console.WriteLine("Got {0}", sample);

        sample.Value = 2;

        Console.WriteLine("Changed to {0}", sample);

        sample = new Sample(3);

        Console.WriteLine("Replaced instance to {0}", sample);

    }

    public static void WithRef(ref Sample sample)

    {

        Console.WriteLine("Got {0}", sample);

        sample.Value = 2;

        Console.WriteLine("Changed to {0}", sample);

        sample = new Sample(3);

        Console.WriteLine("Replaced instance to {0}", sample);

    }

}

​

public class Sample

{

    public Sample(int value)

    {

        this.Value = value;

    }

    public int Value { get; set; }

    public override string ToString()

    {

        return string.Format("Sample({0})", this.Value);

    }

}