打印浮点数值

最新推荐文章于 2024-12-05 14:40:21 发布

原创最新推荐文章于 2024-12-05 14:40:21 发布 · 287 阅读

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#c语言

本文介绍了一种在C语言中打印浮点数值的方法，通过`device_printf_float_pn_data`函数，根据精度要求（1到6位小数）进行格式化输出，包括负数的处理和单位的添加。

对于不能使用printf直接打印浮点数据的可以借鉴

#include <stdio.h>
#include <string.h>
int device_printf_float_pn_data(int level,char *str_name,float data,int pn,char * str_unit)
{
   char flag[2] = {0,0};
   int data_i = 0;
   if(strlen(str_name) > 20)
   {
       printf("str_name len more than 20 err\n");
       return -1;
   }
   if(strlen(str_unit) > 20)
   {
       printf("str_unit len more than 20 err\n");
       return -1;
   }
   if(data <(float)0.0)
   {
       data = (float)0.0- data;
       flag[0] = '-';//符号
       data_i= (int )data;
   }
   else
   {
       data_i= (int )data;
   }
   switch(pn)
   {
       case 5:
           printf("%s = %s%d.%05d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)100000.0+0.5),str_unit);
       break;
       case 4:
           printf("%s = %s%d.%04d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)10000.0+0.5),str_unit);
       break;
       case 3:
           printf("%s = %s%d.%03d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)1000.0+0.5),str_unit);
       break;
       case 2:
           printf("%s = %s%d.%02d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)100.0+0.5),str_unit);
       break;
       case 1:
           printf("%s = %s%d.%01d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)10.0+0.5),str_unit);
       break;
       case 6:
           printf("%s = %s%d.%06d %s\n",str_name,flag,data_i,(int)((data-(float)data_i)*(float)1000000.0+0.5),str_unit);
       break;
       default:
           break;
   }


   return 0;
}
int main()
{
/* Write C code in this online editor and run it. */
printf("Hello, World! \n");
device_printf_float_pn_data(1,(char *)"TEMP123456789",-20.5812345f,1,(char *)"C");
   device_printf_float_pn_data(1,(char *)"TEMP123456789",-20.5812345f,2,(char *)"C");
   device_printf_float_pn_data(1,(char *)"TEMP123456789",-20.5812345f,3,(char *)"C");
   device_printf_float_pn_data(1,(char *)"TEMP123456789",-20.5812345f,4,(char *)"C");
   device_printf_float_pn_data(1,(char *)"TEMP123456789",20.58f,5,(char *)"C");
   device_printf_float_pn_data(1,(char *)"TEMP123456789",-20.5812646f,6,(char *)"C");
return 0;
}

Hello, World!
TEMP123456789 = -20.6 C
TEMP123456789 = -20.58 C
TEMP123456789 = -20.581 C
TEMP123456789 = -20.5812 C
TEMP123456789 = 20.58000 C
TEMP123456789 = -20.581265 C