Dictionary C# Example

C# > Generics > Dictionary 

Dictionary is a collection of keys and values.
Retrieving a value by using its key is very fast because the Dictionary class is implemented as a hash table.

Example

    Dictionary<string, string> accesCode = new Dictionary<string, string>();

            accesCode.Add("AAA", "PERSON 1");

            accesCode.Add("BBB", "PERSON 2");

            accesCode.Add("CCC", "PERSON 3");

            string code = "";

            accesCode.TryGetValue("xxx", out code); // code = null

            accesCode.TryGetValue("CCC", out code); // code = PERSON 3

            if (!accesCode.ContainsKey("DDD"))

                accesCode.Add("DDD", "PERSON 4");

            foreach (KeyValuePair<string, string> kvp in accesCode)

            {

                MessageBox.Show(kvp.Key + kvp.Value);

            }