C# preprocessor directives
This section contains information about the following C# preprocessor directives:
- #if
- #else
- #elif
- #endif
- #define
- #undef
- #warning
- #error
- #line
- #nullable
- #region
- #endregion
- #pragma
- #pragma warning
- #pragma checksum
See the individual topics for more information and examples.
Although the compiler doesn't have a separate preprocessor, the directives described in this section are processed as if there were one. They are used to help in conditional compilation. Unlike C and C++ directives, you cannot use these directives to create macros.
A preprocessor directive must be the only instruction on a line.