C/Macro Preprocessor/Preprocessor IF
IF and endif preprocessor
#include <stdio.h>
#define TEST 29
#if defined TEST
int main(void)
{
printf("This is a test.\n");
return 0;
}
#endif
ifdef preprocessor
#include <stdio.h>
#define DOG
int main(void)
{
#ifdef DOG
printf("DOG is defined.\n");
#endif
#undef DOG
#ifdef DOG
printf("This line is not compiled.\n");
#endif
return 0;
}
#IF #ELSE #ENDIF
//file1.h
#define USD 1
//file2.h
#define UKP 1
//file3
#include <stdio.h>
#include <file1.h>
#if (defined (USD))
#define currency_rate 46
#else
#define currency_rate 100
#endif
main() {
int rs;
rs = 10 * currency_rate;
printf ("d\n", rs);
}