Part 4. C# 4: Playing nicely with others

C# 4 is a funny beast. It doesn’t have the “several, almost unrelated, major new features” feeling of C# 2, nor the “all in the cause of LINQ” feeling of C# 3. Instead, the new features of C# 4 fall somewhere between the two. Interoperability is a major theme, but many of the features are equally useful even if you never need to work with other environments.

My personal favorite features from C# 4 are optional parameters and named arguments. They’re relatively simple but can be put to good use in many places, improving the readability of code and generally making life more pleasant. Do you waste time working out which argument means what? Put some names on them. Are you tired of writing endless overloads to avoid callers having to specify everything? Make some parameters optional.

If you work with COM, C# 4 will be a breath of fresh air for you. To start with, the features I just described make some APIs much simpler to work with, where the component designers have pretty much assumed that you’ll be working with a language supporting optional parameters and named arguments. Beyond that, there’s a better deployment story, support for named indexers, and a helpful shortcut to avoid having to pass arguments by reference everywhere. The biggest feature of C# 4—dynamic typing—also makes COM integration easier.