C# preprocessor include file

Active Oldest Votes. No, it isn't. However, you can wrap both entire files in if blocks. Improve this answer. SLaks SLaks k gold badges silver badges bronze badges. Also don't forget that partial classes and partial methods can be extremely useful in cases like that. Dean Harding Dean Harding In C we don't use an include of a file, but you can use conditional methods. The link is half-broken "Visual Studio Retired Technical documentation". Dave Markle Dave Markle Sign up or log in Sign up using Google.

Explore Python Examples. Popular Examples Add two numbers. Check prime number. Find the factorial of a number. Print the Fibonacci sequence. Check leap year. Related Topics C using. C if, if The preprocessor directives available in C are: Preprocessor directives in C Preprocessor Directive Description Syntax if Checks if a preprocessor expression is true or not if preprocessor-expression code to compile endif elif Used along with if to check multiple preprocessor expressions if preprocessor-expression-1 code to compile elif preprocessor-expression-2 code to compile endif else Used along with if to create compound conditional directive.

Symbols that are defined when used along with if directive will evaluate to true. These symbols can be used to specify conditions for compilation. Undefined symbols when used along with if directive will evaluate to false. The codes inside the if directive is compiled only if the expression tested with if evaluates to true. It is used when testing multiple preprocessor expression. The codes inside the elif directive is compiled only if the expression tested with that elif evaluates to true.

If you enclose a complete, unambiguous path specification for the include file between double quotation marks " " , the preprocessor searches only that path specification and ignores the standard directories. If the file name that's enclosed in double quotation marks is an incomplete path specification, the preprocessor first searches the parent file's directory. A parent file is the file that contains the include directive. For example, if you include a file named file2 in a file named file1 , file1 is the parent file.

Include files can be nested : An include directive can appear in a file that's named by another include directive. For example, file2 could include file3. In this case, file1 would still be the parent of file2 , but it would be the grandparent of file3. When include files are nested and when compiling occurs on the command line, directory searching begins in the directory of the parent file. Then it proceeds through the directories of any grandparent files.

That is, searching begins relative to the directory that contains the source that's currently being processed. The values specified in the project properties for include directories are used instead. For more information about how to set the include directories in Visual Studio, see Include Directories and Additional Include Directories.

The C preprocessor is a macro processor that the C compiler automatically uses to transform your program before actual compilation. The C preprocessor allows you to define macros, which are brief abbreviations for longer constructs. A preprocessor directive must be the only instruction on a line. Preprocessing directives start with , followed by an identifier that is the directive name.

For example, define is the directive. White space is allowed before and after the. The C language's preprocessor directives are as follows:. The main uses of directives include conditional compilation, line control, error and warning reporting, and region and end region. Let's take a preliminary look at each. Conditional compilation: Using special preprocessing directives, you can include or exclude parts of the program according to various conditions.