ID : 501
Preprocessor
Preprocessor refers to string processing performed before program compilation.
As the preprocessor is processed before compilation, variables, procedures and commands that are valid after compilation are processed as mere strings. Therefore, variables cannot be used and it can be described whether in or out of the procedure.
Its processes includes:
- File reading (#Include, etc.)
- Macro expansion (#Define, #Undef)
- Partial selection of source code by compilation conditions (#If ... #Endif, etc.)
- Processing of encrypted program codes (#Pragma Encrypt)
- Alert during compilation (#Warning, #Error)
List of Preprocessor Codes
Command name | Function |
---|---|
#Define | To define macro. |
#Undef | To cancel the macro definition defined by #Define (set to undefined). |
#Include | To read a designated file. |
#Pragma Encrypt | To encrypt a program code. |
#If ... #Endif | To select a program code to compile according to specified conditions. |
#Ifdef ... #Endif | To determine whether the designated macro is defined and select a program code to compile. |
#Ifndef ... #Endif | To determine whether the designated macro is not defined and select a program code to compile. |
#Warning | To output a warning at the time of compiling. |
#Error | To output an error at the time of compiling. |
Related Terms
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Attention
Preprocessor codes are processed before compilation. Therefore, variables to be declared in a program cannot be used.
ID : 501
- Related Information
- Preprocessor Format
- Macro Definition
- Program Code Encryption