A discussion of the new language features of C# 4.0, emphasizing on the dynamic programming capabilities of the language and its ability to define objects at runtime

1. Jon Limjap Microsoft Most Valuable Professional for Visual C# Senior Application Developer, FBM e-Services Dynamics & Object Runtime Composition with C# 4.0

2. ? Do you use C#

3. ? Is C#... static dynamic

4. static dynamic C# 4.0

5. Microsoft .NET Dynamic Language Runtime

6. Why dynamic?

7. Expressiveness Tell me what to do… …not how to do it

8. Duck Typing If it quacks, it’s a duck!

9. Object Runtime Modification Object types can be modified on runtime

10. Dynamic at compile time dynamic myObj = "blah"; System.String at run time

11. dynamic myObj = "blah"; Console.WriteLine(myObj.Contains("lah"));Console.WriteLine(myObj.IndexOf("x"));Console.WriteLine(myObj.GetType());myObj = new List<int>();Console.WriteLine(myObj.Count);Console.WriteLine(myObj.GetType()); Change of type here But no compiler errors! Method signature doesn’t match initial type

12. Requires System.Dynamic dynamic mrFantastic = new ExpandoObject();mrFantastic.Name = "Reed Richards";mrFantastic.BirthDate = new DateTime(year: 1961, month: 12, day: 2);Console.WriteLine(mrFantastic.Name);Console.WriteLine(mrFantastic.BirthDate); Properties can be added during runtime

13. mrFantastic.SayMyName = new Action( () => Console.WriteLine(mrFantastic.Name));mrFantastic.GetAge = new Func<int>( () => Convert.ToInt32( (DateTime.Now - mrFantastic.BirthDate).Days / 365.25));mrFantastic.SayMyName();Console.WriteLine(mrFantastic.GetAge()); Methods could be added using Action<T> & Func<T>

14. jonlimjap@gmail.com http://twitter.com/LaTtEX http://dotnet.kapenilattex.com