alltypes.c

C语言常用的程序900例

#include <stdio.h>
#include <stdarg.h>

double add_values(char *str, ...)
{
    va_list marker;
    
    double result = 0.0;

    va_start(marker, str);  /* mark first additional argument */

    while (*str)            /* examine each character in the string */
      {
	if (*str == '%')    /* if not a %_ format specifier, skip it */
	  {
	    switch (*(++str)) {
		case 'd': result += va_arg(marker, int);
			  break;
		case 'f': result += va_arg(marker, double);
			  break;
	      }
	  }
	str++;
      }
   
   va_end(marker);
   return(result);
 }
 

void main(void)
 { 
   double result;

   printf("Result %f\n", add_values("%f", 3.3));
   printf("Result %f\n", add_values("%f %f", 1.1, 2.2));
   printf("Result %f\n", add_values("%f %d %f", 1.1, 1, 2.2));
   printf("Result %f\n", add_values("%f %d %f %d", 1.1, 1, 2.2, 3));
 }