floor

函数名: floor

功 能: 向下舍入

用 法: double floor(double x);

包含于头文件:math.h

程序例:

#include <stdio.h>

#include <math.h>

int main(void)

{

double number = 123.54;

double down, up;

down = floor(number);

up = ceil(number);

printf("original number %10.2lf

",number);

printf("number rounded down %10.2lf

",down);

printf("number rounded up %10.2lf

",up);

return 0;

}

运行结果：

original number 123.54

number rounded down 123.00

number rounded up 124.00