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// Assume we have an array of strings.

string[] currentVideoGames = {"Morrowind", "BioShock",

"Half Life 2: Episode 1", "The Darkness",

"Daxter", "System Shock 2"};

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// Build a query expression to represent the items in the array

// that have more than 6 letters.

IEnumerable subset = from g in currentVideoGames

where g.Length > 6 orderby g select g;

// Print out the results.

foreach (string s in subset)

Console.WriteLine("Item: {0}", s);

}

Notice that the query expression created here makes use of the from, in, where, orderby,

and select LINQ query operators. We will dig into the formalities of query expression syntax in

just a bit, but even now you should be able to parse this statement as “Give me the items inside of

currentVideoGames that have more than six characters, ordered alphabetically.” Here, each item that

matches the search criteria has been given the name “g” (as in “game”); however, any valid C# vari-

able name would do:

IEnumerable subset = from game in currentVideoGames

where game.Length > 6 orderby game select game;

Notice that the “result set” variable, subset, is represented by an object that implements the

generic version of IEnumerable, where T is of type System.String (after all, we are querying an

array of strings). Once we obtain the result set, we then simply print out each item using a standard

foreach construct.

Before we see the results of our query, assume the Program class defines an additional helper

function named ReflectOverQueryResults() that will print out various details of the LINQ result set

(note the parameter is a System.Object, to account for multiple types of result sets):

static void ReflectOverQueryResults(object resultSet)

{

Console.WriteLine("***** Info about your query *****");

Console.WriteLine("resultSet is of type: {0}", resultSet.GetType().Name);

Console.WriteLine("resultSet location: {0}", resultSet.GetType().Assembly);

}

Assuming you have called this method within QueryOverStrings() directly after printing

out the obtained subset, if you run the application, you will see the subset is really an instance

of the generic OrderedEnumerable type (represented in terms of CIL code as

OrderedEnumerable`2), which is an internal abstract type residing in the System.Core.dll assembly

(see Figure 14-2).

Figure 14-2.

The result of our LINQ query

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