C语言可变参函数

#ifndef VARARGS_H

#define VARARGS_H

#include 

extern double sum(int, ...);

double sum(int lim, ...)

{

 va_list ap;

 double tot = 0;

 int i;

 va_start(ap, lim);

 for(i = 0; i < lim; i++)

 {

 tot += va_arg(ap, double);

 }

 va_end(ap);

 return tot;

}

#endif // VARARGS_H

//varargs.c--使用可变个数的参数
#include 
#include "varargs.h"

int main(void)
{
 double s, t;

 s = sum(3, 1,1, 2.5, 13.3);
 t = sum(6, 3.4, 5.6, 3.1, 5.8, 9.3, 23.3);

 printf("The return value is '%g'\n",s);
 printf("The return value is '%g'\n",t);
 return 0;
}