C# differ from C++

Question

Hi
How does C# differ from C++?

Vulpes · Answer

Here are some of the main differences between standard (i.e. unmanaged C++) and C#:
1. A C# compiler produces IL (intermediate language) and metadata whereas a C++ compiler produces native code.
2. A C# program runs under the control of the CLR (common language runtime) which converts the intermediate language to native code 'on the fly'. This means that there is less opportunity for optimizations than in a C++ program but it also means that account can be taken of information available at runtime which was not available at compile time.
3. Execution speed in C++ is generally better than C# but development takes longer.
4. The automatic production of metadata in a C# program means that there is no need to include 'header' files as there is in a C++ program.
5. The order of classes in a C# program is immaterial whereas C++ classes need to be defined (or at least declared) before they can be used.
6. In C#, objects created from classes (known as 'reference types') are always stored on the heap and are automatically cleaned up by the CLR's garbage collector when there are no longer any references to them. In C++ you have to destroy objects manually.
7. In C# structs are used to define lightweight 'value' types which can be stored on the stack, whereas in C++ structs are the same as classes except that members are public (rather than private) by default.
8. In C# pointers can only be used in 'unsafe' code.
9. C++ permits the use of global variables and functions but C# does not.
10. C++ supports multiple inheritance but C# only supports single inheritance. However, you can also implement multiple interfaces in C#.
11. C# supports RAD (rapid application development) features such as properties and events, but C++ does not.
12. C# supports LINQ (lanaguage integrated query) but C++ does not.
13. C#'s switch statement supports string as well integer cases and does not allow 'fall through' between cases, unless they are empty.
14. In C# there is no automatic conversion between bool and the integral types.
15. In C# strings are always unicode. C++ supports both ANSI and unicode strings.
16. C++ supports macros but C# does not.
17. C++ supports const functions or parameters but C# does not.
18. Unlike C++, C# does not have its own runtime library but instead shares the .NET Framework class libraries with other .NET languages.