About

C# is a multiparadigm, managed, garbage-collected object-oriented programming language created by Microsoft in conjunction with the .NET platform, but also used with non-Microsoft implementations (most notably, Mono).

Versions 1.0/1.2 and 2.0 of C# were submitted and approved as both ECMA and ISO/IEC standards. As of December 2010, there are no ECMA or ISO/IEC specifications for C# 3.0 and 4.0, however language specifications are available from Microsoft (3.0 and 4.0 respectively).

The language's type-system was originally static, with only explicit variable declarations allowed. However, the introduction of var (C# 3.0) and dynamic (C# 4.0) allow it to use type-inference for implicit variable typing, and to consume dynamic type-systems, respectively. Delegates (especially with lexical-closure support for anonymous-methods (C# 2.0) and lambda-expressions (C# 3.0)) allow the language to be used for functional programming.

Compilation is usually to the Common Intermediate Language (CIL), which is then JIT-compiled to native code (and cached) during execution in the Common Language Runtime (CLR); however, options like Ngen (.NET) and AOT (Mono) mean this isn't the only option. Additionally, some frameworks (e.g. the Micro Framework) act as CIL interpreters, with no JIT.

Perhaps unusually, generics in C# are provided (in part) by the runtime, unlike (for comparison) C++ templates, or Java's generics (which use type-erasure).

With the combination of Microsoft .NET for Windows (desktop/server), Mono (desktop/server/mobile), Silverlight / Moonlight (browser/mobile), Compact Framework (mobile), and Micro Framework (embedded devices), it is available for a wide range of platforms.

Hello World

using System;
class Hello
{
    static void Main() 
    {
        Console.WriteLine("Hello, World");
    }
}

FAQs

• What are the correct version numbers for C#?
• Why is Random giving the same results every time?
• Captured variables in loops
• Why can't I convert List<Banana> to List<Fruit>?
• Does C# pass objects by reference?

Resources

• Specification
• Wikipedia Article
• Eric Lippert's blog
• Programming Guide
• Books
  • CLR via C#
  • C# in a Nutshell
  • C# in Depth
  • Accelerated C#
  • Head First C#
  • The C# Programming Language (3rd Edition, 4th Edition)
  • Framework Design Guidelines
  • Essential C# (4.0 (3rd Edition))