The C# FAQ for C++ programmers was first posted in Aug 2000, and is regularly updated. It answers many of the questions that C++ developers have when they first encounter C#.
1. Introduction
1.1 What is C#?
C# is a programming language designed by Microsoft. It is loosely based on C/C++, and bears a striking similarity to Java. Microsoft describe C# as follows:
"C# is a simple, modern, object oriented, and type-safe programming language derived from C and C++. C# (pronounced 'C sharp') is firmly planted in the C and C++ family tree of languages, and will immediately be familiar to C and C++ programmers. C# aims to combine the high productivity of Visual Basic and the raw power of C++."
You can get the ECMA C# spec in PDF form here, or use Jon Jagger's html version.
1.2 How do I develop C# apps?
The (free) .NET SDK contains the C# command-line compiler (csc.exe). Visual Studio has fully integrated support for C# development. On Linux you can use Mono.
1.3 Does C# replace C++?
There are three options open to the Windows developer from a C++ background:
Stick with standard C++. Don't use .NET at all.
Use C++ with .NET. Microsoft supply a .NET C++ compiler that produces IL rather than machine code. However to make full use of the .NET environment (e.g. garbage collection), a set of extensions are required to standard C++. In .NET 1.x this extended language is called Managed Extensions for C++. In .NET 2.0 ME C++ has been completely redesigned under the stewardship of Stan Lippman, and renamed C++/CLI.
Forget C++ and use C#.
Each of these options has merits, depending on the developer and the application. For my own part, I intend to use C# where possible, falling back to C++ only where necessary. ME C++ (soon to be C++/CLI) is very useful for interop between new .NET code and old C++ code - simply write a managed wrapper class using ME C++, then use the managed class from C#. From experience, this works well.
1.4 Does C# have its own class library?
Not exactly. The .NET Framework has a comprehensive class library, which C# can make use of. C# does not have its own class library.
