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C Preprocessors Programs

By IncludeHelp Last updated : March 10, 2024

In C programming language, the preprocessors are the programs that process the source code before the compilation. We can say that preprocessors are not the part of the program compilation, it's a separate process which process the code before the compilation.

C Preprocessor Directives

There are following preprocessor directives in C programming language,

Preprocessor Directives	Description
#define	To define a preprocessor macro.
#include	To include the code from another file or to include header file in the current code.
#undef	To undefine a defined preprocessor macro.
#ifdef	To check whether a macro is defined or not, it returns true if macro is defined.
#ifndef	To check whether a macro is defined or not, it returns true if macro is not defined.
#if, #else, #elif, #endif	To control the compilation of portions of a source code.
#error	To print the error message on stderr.
#pragma	To issue special commands to the compiler, using a standardized method.

C Preprocessors Programs (Examples)

This section contains the C solved programs on C preprocessors, practice these programs to learn the concept of C preprocessors. Each program contains the solved code, output and explanations.

List of C Preprocessors Programs

1. The #if directive Example in C
2. The #if ... #else directive Example in C
3. The # Preprocessor Operator Example in C
4. The ## Preprocessor Operator Example in C
5. The __LINE__ Macro Example in C
6. Print the current function name by using __func__ in C
7. The #line directive Example in C
8. Define Macros for YES and NO constants using #define in C
9. Define a function like Macro that should use printf in C
10. Define Macro PRINT to print given integer argument in C
11. Define Macros to SET and CLEAR bit of a PIN in C
12. Define Macro to toggle a bit of a PIN in C
13. Define a Macro to set Nth bit to Zero in C
14. Define a constant using Macro to use in Array declarations in C
15. How to redefine a Macro in C?
16. How to check whether a Macro is defined or not in C?
17. Print argument (i.e. variable name, value) using Macro in C
18. Print error message from any function with function name, line number in C.
19. Macro Arguments Evaluation in C
20. Define a Macro to find total number of elements in C
21. Define a Macro to round a float value to nearest integer in C
22. C program to print the function names defined in the source code
23. C program to print the name of the source code file
24. C program to print the line number in source code with filename and function name