using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        MethodOne();

        MethodTwo();

    }

    public static void MethodOne(){

        var dict1 = new Dictionary<string, string>();

        dict1.Add("k1", "v1");

        dict1.Add("k2", "v2");

        dict1.Add("k3", "v3");

        dict1.Add("k4", "v4");

        dict1.Add("k5", "v5");

        var dict2 = dict1;

        dict1.Add("k6", "v6");

        foreach(var entry in dict2) {

            Console.WriteLine("MethodOne Dict2: " + entry);

        }

        Console.WriteLine("");

        foreach(var entry in dict1) {

            Console.WriteLine("MethodOne Dict1: " + entry);

        }

    }

    public static void MethodTwo() {

        var dict1 = new Dictionary<string, string>();

        var dict2 = new Dictionary<string, string>();

        dict1.Add("k1", "v1");

        dict1.Add("k2", "v2");

        dict1.Add("k3", "v3");

        dict1.Add("k4", "v4");

        dict1.Add("k5", "v5");

        foreach(var entry in dict1) {

            dict2[entry.Key] = entry.Value;

        }

        Console.WriteLine("");

        dict1.Add("k6", "v6");

        foreach(var entry in dict2) {

            Console.WriteLine("MethodTwo Dict2: " + entry);

        }

        Console.WriteLine("");

        foreach(var entry in dict1) {

            Console.WriteLine("MethodTwo Dict1: " + entry);

        }

    }

​

}