using System;

public class Program

{

    public static void Main()

    {

        int n = 10;

        Console.WriteLine(n);

        Times2(ref n);

        Console.WriteLine(n);

        Number num = new Number();

        Console.WriteLine(num.Value);

        ValueTimes2(ref num);

        Console.WriteLine(num.Value);

    }

    public static void Times2(ref int n){

        n *= 2;

    }

    public static void ValueTimes2(ref Number n){

        n.Value *= 2;

    }

}

​

public class Number{

    public int Value = 10;

}

​

​