This print for content only-size & color not accurate 7" X 9-1/4" / casebound / malloy

// Get items using GetEnumerator().

foreach (Car c in carLot)

{

Console.WriteLine("{0} is going {1} MPH",

c.PetName, c.Speed);

}

Console.WriteLine();

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---

// Get items (in reverse!) using named iterator.

foreach (Car c in carLot.GetTheCars(true))

{

Console.WriteLine("{0} is going {1} MPH",

c.PetName, c.Speed);

}

Console.ReadLine();

}

Named iterators are helpful constructs, in that a single custom container can define multiple

ways to request the returned set.

Internal Representation of an Iterator Method

When the C# compiler encounters an iterator method, it will dynamically generate a nested class

definition within the scope of the defining type (Garage in this case). The autogenerated nested

class implements the GetEnumerator(), MoveNext(), and Current members on your behalf (oddly,

the Reset() method is not, and you will receive a runtime exception if you attempt to call it). If you

were to load the current application into ildasm.exe, you would find two nested types, each of

which accounts for the logic required by a specific iterator method. Notice in Figure 9-10 that these

compiler-generated types have been named d__0 and d__5.

Figure 9-10.

Iterator methods are internally implemented with the help of an autogenerated

nested class.

If you used ildasm.exe to view the implementation of the GetEnumerator() method of the

Garage type, you’d find that it has been implemented to make use of the d__0 type

behind the scenes (the nested d__5 type is used by the GetTheCars() method in a simi-

lar manner).

.method public hidebysig instance class

[mscorlib]System.Collections.IEnumerator