using System;

using System.Collections.Generic;

using System.IO;

​

public class Program

{

    public static void Main()

    {

        var myA = new A();

        myA.fillList();

        foreach (var item in myA.details)

        {

            Console.WriteLine(item);

        }

    }

}

​

public class A

{

    public List<string> details;

    public void fillList()

    {

        details = new List<string>();

        details.Add("abc");

        details.Add("xyz");

    }

}