C语言条件编译实例

/* ifdef.c -- uses conditional compilation */
#include <stdio.h>
#define JUST_CHECKING
#define LIMIT 4

int main(void)
{
    int i;
    int total = 0;

    for (i = 1; i <= LIMIT; i++)
    {
        total += 2*i*i + 1;
#ifdef JUST_CHECKING
        printf("i=%d, running total = %d\n", i, total);
#endif
    }
    printf("Grand total = %d\n", total);

    return 0;
}