The C programming language supports preprocessors in order to work the program efficiently.C preprocessoris a macro preprocessor for C-based programming languages. The preprocessor provides the compiler with the ability to include header files, macro expansion, conditional compilation, and line control in an explicit manner.
#hashtag is used to define preprocessors, that is, all preprocessors start with #. This is followed by the name of the preprocessor without any spaces. Here is a list of C preprocessors.
| S.No. | Preprocessor | Description |
|---|---|---|
| 1. | #include | Include specific header files from a file. |
| 2. | #define | Define preprocessor macros. |
| 3. | #undef | Undefine preprocessor macro |
| 4. | #if | Checks the compile-time condition and evaluates toTruevalue. |
| 5. | #else | Evaluate as an alternative to if preprocessor . |
| 6. | #ifndef | Checks whether the macro is defined. If undefined, evaluates to TRUE . |
| 7. | #elif | Simultaneously combine#ifand#elsestatements. |
| 8. | #error | Defined bystderrmethod Printed error message. |
| 9. | #endif | End preprocessor condition. |
| 10. | #pragma | Used to issue commands to the compiler/ |
The above is the detailed content of C preprocessor?. For more information, please follow other related articles on the PHP Chinese website!
What are the advantages of mongodb database
Regular expression usage of arbitrary characters
Representation method of string constant
What are non-relational databases?
gt540
How to use the norm function in python
How to solve the problem that Apple cannot download more than 200 files
Will the Bitcoin inscription disappear?
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
