怎样rounded off/on 价钱在C

JunL

急。。。。要怎样code??只差这部分。。。
用floor 和 ceil function
例如我的total_charge>=RM 39.85
  
  只自动变RM39.90
   如果total_charge <= RM39.84
  就变RM 39.80

kkwpms99

use round function

JunL

有例子吗？？我想不到coding

mayamaya

#include <math.h>
float round(float x);

int main(void){
float valL = 39.85;
float valS = 39.84;
round(valL);//you will get 39.9
round(valS);//you will get 39.8
return 0;
}

float round(float x){
        float const shift = powf(10.0f,1);
        return floorf(x*shift+0.5f)/shift;
}