This chapter covers the core concepts of C# and .NET, starting from the initial version and principal motivations behind its creation, and covering also the new aspects of the language, that appeared in versions 2.0 and 3.0.
We'll illustrate all the main concepts with small code snippets, short enough to facilitate its understanding and easy reproduction.
In this chapter, we will cover the following topics:
- C# and its role in the Microsoft Development ecosystem
- Difference between strongly typed and weakly typed languages
- The evolution in versions 2.0 and 3.0
- Generics
- Lambda expressions
- LINQ
- Extension methods
I had the chance to chat with Hejlsberg a couple of times about the C # language and what the initial purposes and requirements imposed in its creation were and which other languages inspired him or contributed to his ideas.
The first time we talked, in Tech-Ed 2001 (at Barcelona, Spain), I asked him about the principles of his language and what makes it different from others. He first said that it was not only him who created the language, but also a group of people, especially Scott Wiltamuth, Peter Golde, Peter Sollich, and Eric Gunnerson.
About the principles, he mentioned this:
"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++. But beyond these more traditional language issues, one of our key design goals was to make the C# language component-oriented, to add to the language itself all of the concepts that you need when you write components. Concepts such as properties, methods, events, attributes, and documentation are all first-class language constructs."
He stated also this:
"When you write code in C#, you write everything in one place. There is no need for header files, IDL files (Interface Definition Language), GUIDs and complicated interfaces."
This means that you can write code that is self-descriptive in this way given that you're dealing with a self-contained unit (let's remember the role of the manifest, optionally embedded in assemblies). In this mode, you can also extend existing technologies in a variety of ways, as we'll see in the examples.