C# in Depth

Part 2C#2:solving the issuesof C#1In part 1 we took a quick look at a few of the features of C# 2. Now it’s time todo the job properly. We’ll see how C# 2 fixes various problems that developersran into when using C# 1, and how C# 2 makes existing features more useful bystreamlining them. This is no mean feat, and life with C# 2 is much more pleasantthan with C# 1.The new features in C# 2 have a certain amount of independence. That’s notto say they’re not related at all, of course; many of the features are based on—orat least interact with—the massive contribution that generics make to the language.However, the different topics we’ll look at in the next five chapters don’tcombine into one cohesive whole.The first four chapters of this part cover the biggest new features. We’ll lookat the following:■ Generics-—The most important new feature in C# 2 (and indeed in theCLR for .NET 2.0), generics allow type and method parameterization.■ Nullable types —Value types such as int and DateTime don’t have any conceptof “no value present”—nullable types allow you to represent theabsence of a meaningful value.■ Delegates —Although delegates haven’t changed at the CLR level, C# 2makes them a lot easier to work with. As well as a few simple shortcuts, theintroduction of anonymous methods begins the movement toward a morefunctional style of programming—this trend continues in C# 3.■ Iterators —While using iterators has always been simple in C# with theforeach statement, it’s a pain to implement them in C# 1. The C# 2 compileris happy to build a state machine for you behind the scenes, hiding alot of the complexity involved.Licensed to Rhona Hadida