using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        IDictionary<int, string> numberNames = new Dictionary<int, string>();

        numberNames.Add(1,"One"); //adding key/value using the Add() method

        numberNames.Add(3,"Three");

        numberNames.Add(2,"Two");

        foreach(KeyValuePair<int, string> kvp in numberNames)

            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);

        //creating a dictionary using collection-initializer syntax

        var cities = new Dictionary<string, string>(){

            {"UK","London, Manchester, Birmingham"},

            {"USA","Chicago, New York, Washington"},

            {"India","Mumbai, New Delhi, Pune"}

        };

        foreach(var kvp in cities)

            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);

    }

}