C++ floor函數 截斷符點數小數部分

函數原型：

double floor ( double x );

float floor ( float x );

long double floor ( long double x );

功能：返回一個小於傳入參數的最大整數

參數：x爲將來被處理的數

返回值：返回不大於x的最大整數

示例程序：

#include <stdio.h>
#include <math.h>

int main ()
{
    printf ("floor of 2.3 is %.1lf/n", floor (2.3) );
    printf ("floor of 2.6 is %.1lf/n", floor (2.6) );
    printf ("floor of -2.3 is %.1lf/n", floor (-2.3) );
    printf ("floor of -2.6 is %.1lf/n", floor (-2.6) );
    return 0;
}

輸出：

floor of 2.3 is 2.0
floor of 2.6 is 2.0
floor of -2.3 is -3.0
floor of -2.6 is -3.0