C语言可变参数使用示例

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

double average(int num,...)
{

va_list valist;
double sum = 0.0;
int i;

/* 为 num 个参数初始化 valist */
va_start(valist, num);

/* 访问所有赋给 valist 的参数 */
for (i = 0; i < num; i++)
{
sum += va_arg(valist, int);
}
/* 清理为 valist 保留的内存 */
va_end(valist);

return sum/num;
}

int main()
{
printf("Average of 2, 3, 4, 5 = %f\n", average(4, 2,3,4,5));
printf("Average of 5, 10, 15 = %f\n", average(3, 5,10,15));
}