using System;
using System.Collections.Generic;
public class Program
{
public static void Main()
var dict = new Dictionary<string,string>();
dict["test1"] = "123"; // Add
dict["test2"] = "456"; // Add
dict["test2"] = "abc"; // Update
Console.WriteLine("test1: " + dict["test1"]);
Console.WriteLine("test2: " + dict["test2"]);
}