using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var list1 = new List<int>() { 1, 2, 3 };

        var list2 = list1.Where(x => x > 1).ToList();

        list2.ForEach(x => x++);

        Console.WriteLine(string.Join(", ", list1));

        var list11 = new List<Item>(){

            new Item{ Id = 1, Value = "1"},

            new Item{ Id = 2, Value = "2"},

            new Item{ Id = 3, Value = "3"},

            new Item{ Id = 4, Value = "4"}

        };

        var list22 = list11.Where(i => i.Id > 2).ToList();

        list22.ForEach(i => i.Value = "5");

        list11.ForEach(i => Console.WriteLine(i.Value));

    }

    public class Item {

        public int Id;

        public string Value;

    }

}