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8849CH14.qxd  9/26/07  12:30 PM  Page 465

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var makes = (from c in myCars select c.Make).Distinct();

When calling any extension method defined by Enumerable, you can do so either at the time

you build the query expression (as shown in the previous example) or via an extension method on a

compatible underlying array type. Thus, the following code yields identical output:

var makes = from c in myCars select c.Make;

Console.WriteLine("Distinct makes:");

foreach (var m in makes.Distinct())

{

Console.WriteLine("Make: {0}", m);

}

Figure 14-7 shows the result of calling BasicSelections().

Figure 14-7.

Selecting basic data from the Car[] parameter

Obtaining Subsets of Data

To obtain a specific subset from a container, you can make use of the where operator. When doing

so, the general template now becomes as follows:

var result = from item in container where Boolean expression select item;

Notice that the where operator expects an expression that resolves to a Boolean. For example,

to extract from the Car[] parameter only the items that have “BMW” as the value assigned to the

Make field, you could author the following code within a new method named GetSubsets():

static void GetSubsets(Car[] myCars)

{

// Now get only the BMWs.

var onlyBMWs = from c in myCars where c.Make == "BMW" select c;

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