using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var hoge1 =　GetHoge();

        hoge1.Dump();

        hoge1.a = 5;

        hoge1.Dump();

        var hogeList = new List<hoge>();

        hogeList.Add(new hoge(){a=2,b=2});

        hogeList.Add(new hoge(){a=4,b=4});

        hogeList.Add(new hoge(){a=6,b=6});

        Console.WriteLine("Original");

        foreach (var hog in hogeList){

            hog.Dump();

        }

        Console.WriteLine("Data Change");

        foreach (var hog2 in hogeList){

            hog2.ChangeA(5);

        }

        foreach (var hog2 in hogeList){

            hog2.Dump();

        }

    }

    public static hoge GetHoge()

    {

        return new hoge(){a=1,b=2};

    }

    public struct hoge{

        public int a;

        public int b;

        public void ChangeA(int a)

        {

            this.a = a;

        }

        public void Dump()

        {

            Console.WriteLine("a:"+a+"b"+b);

        }

    }

}