#include
#define PI 3.1415926
void main(void)
{
float f_radius=2.0;
float f_area=PI*f_radius*f_radius;
float f_circumference =PI*f_radius*2.0;
printf("\nArea=%f,circumference=%f",f_area,f_circumference);
}
printf("\nArea=%d,circumference=%f",f_area,f_circumference); 中的%d改为%f
#define PI 3.1415926
宏定义不用等号