Deep Inside C#: An Interview with Microsoft Chief Architect Anders Hejlsberg

In July, O'Reilly editor John Osborn attended the Microsoft Professional Developer's Conference where he conducted the following interview with Anders Hejlsberg, Distinguished Engineer and Chief C# Language Architect about Microsoft's .Net framework and the C# programming language. Anders Hejlsberg is also known for having designed Turbo Pascal, one of the first languages available for PCs. Anders licensed Turbo Pascal to Borland and later led the team that created Delphi, a highly successful visual design tool for building client server applications. Also in attendance at the interview were Tony Goodhew, Microsoft C# product manager, and O'Reilly Windows editor Ron Petrusha.

Osborn: I've been looking at press stories about C# [pronounced "See sharp"] and notice that many of them seem to lead with the observation -- or perhaps the theory -- that C# is either a clone of or a Microsoft replacement for Java. If you could write the headlines, what would you like people to say about the language?

Hejlsberg: First of all, C# is not a Java clone. In the design of C#, we looked at a lot of languages. We looked at C++, we looked at Java, at Modula 2, C, and we looked at Smalltalk. There are just so many languages that have the same core ideas that we're interested in, such as deep object-orientation, object-simplification, and so on.

One of the key differences between C# and these other languages, particularly Java, is that we tried to stay much closer to C++ in our design. C# borrows most of its operators, keywords, and statements directly from C++. We have also kept a number of language features that Java dropped. Why are there no enums in Java, for example? I mean, what's the rationale for cutting those? Enums are clearly a meaningful concept in C++. We've preserved enums in C# and made them type-safe as well. In C#, enums are not just integers. They're actually strongly typed value types that derive from System.Enum in the .NET base-class library. An enum of type "foo" is not interchangeable with an enum of type "bar" without a cast. I think that's an important difference. We've also preserved operator overloading and type conversions. Our whole structure for name spaces is much closer to C++.

Read the full interview at:http://www.windowsdevcenter.com/pub/a/oreilly/windows/news/hejlsberg_0800.html