Why I started to feel differently about C# | Using Dictionaries

C#Example.cs

// 
// (1) C#: Defining an initializing a dictionary [key type=string, value type=int]
//
Dictionary<string, int> dict = new Dictionary<string, int>()
{
    {"Eve",    101},
    {"George", 150},
    {"Emma",   200}
};
// 
// (2) C#: Searching for any key (string) - an *almost* O(1) operation
// 
if (dict.ContainsKey("James"))
//
// (3) C#: Search for any value (int) - a linear operation
//
if (dict.ContainsValue(120))
//
// (4) C#: Iterating over keys of a dictionary
// 
foreach (string key in dict.Keys)
//
// (5) C#: Iterating over values of a dictionary
//
foreach (int val in dict.Values)
//
// (6) C#: Iterating over key-value pairs of a dictionary
//
foreach (KeyValuePair<string, int> pair in dict)
{
    Console.WriteLine(string.Format("{0} has value {1}", pair.Key, pair.Value));
}
// or better
foreach (var pair in dict)
//
// (7) C#: Adding a key with a corresponding value
//
dict["Janice"] = 300;