Dictionary implements both the generic and nongeneric IDictionary interfaces.
using System; using System.Collections.Generic; class MainClass/*from w w w . j av a2 s. c o m*/ { public static void Main(string[] args) { var d = new Dictionary<string, int>(); d.Add("One", 1); d["Two"] = 2; // adds to dictionary because "two" not already present d["Two"] = 22; // updates dictionary because "two" is now present d["Three"] = 3; Console.WriteLine (d["Two"]); Console.WriteLine (d.ContainsKey ("One")); Console.WriteLine (d.ContainsValue (3)); int val = 0; if (!d.TryGetValue ("onE", out val)) Console.WriteLine ("No val"); // Three different ways to enumerate the dictionary: foreach (KeyValuePair<string, int> kv in d) Console.WriteLine (kv.Key + "; " + kv.Value); foreach (string s in d.Keys) Console.WriteLine (s); foreach (int i in d.Values) Console.WriteLine(i); } }