ref example

namespace Score
{
    using System;

    public class RefExample
    {
        public static void Main()
        {
            int score = 0;

            // no ref
            //IncreaseScoreNoRef(score);
            //Console.WriteLine(score);

            // ref
            IncreaseScoreRef(ref score);
            Console.WriteLine(score);
        }

        public static void IncreaseScoreRef(ref int score)
        {
            score += 10;
        }

        public static void IncreaseScoreNoRef(int score)
        {
            score += 10;
        }
    }
}