Use #define and #undef to control the program logic : undef « Preprocessing Directives « C# / CSharp Tutorial

C# / CSharp Tutorial
1. Language Basics
2. Data Type
3. Operator
4. Statement
5. String
6. struct
7. Class
8. Operator Overload
9. delegate
10. Attribute
11. Data Structure
12. Assembly
13. Date Time
14. Development
15. File Directory Stream
16. Preprocessing Directives
17. Regular Expression
18. Generic
19. Reflection
20. Thread
21. I18N Internationalization
22. GUI Windows Forms
23. 2D
24. Design Patterns
25. Windows
26. XML
27. ADO.Net
28. Network
29. Directory Services
30. Security
31. unsafe
Java
Java Tutorial
Java Source Code / Java Documentation
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorial
C# / C Sharp
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
C# / CSharp Tutorial » Preprocessing Directives » undef 
16. 4. 1. Use #define and #undef to control the program logic
  1. The #undef directive removes a previously defined definition.
  2. The #undef directive "undefines" a symbol.

The general form for #undef is

#undef symbol
#define win2000
#define release
#undef  win98

using System;
using System.Diagnostics;


class MainClass
{
    public static void Main()
    {
        string platformName;

        #if winXP       // Compiling for Windows XP
            platformName = "Microsoft Windows XP";
        #elif win2000   // Compiling for Windows 2000
            platformName = "Microsoft Windows 2000";
        #elif winNT     // Compiling for Windows NT
            platformName = "Microsoft Windows NT";
        #elif win98     // Compiling for Windows 98
            platformName = "Microsoft Windows 98";
        #else           // Unknown platform specified
            platformName = "Unknown";
        #endif

        Console.WriteLine(platformName);

    }
}
Microsoft Windows 2000
16. 4. undef
16. 4. 1. Use #define and #undef to control the program logic
16. 4. 2. define OS constant for compilation
w_w___w___.j_a_va___2___s._c_om | Contact Us
Copyright 2003 - 08 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.