C可变参数列表

//
//  main.c
//  test
//
//  Created by cbd on 01/01/2017.
//  Copyright © 2017 cbd. All rights reserved.
//

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


int64_t sum(int c_num, ...);

int main(int argc, const char * argv[]) {

    int64_t result = sum(3, 1,2,3);

    //int	 printf(const char * __restrict, ...) __printflike(1, 2);
    printf("sum: %lld\n", result);

    return EXIT_SUCCESS;
}


/**
 任意多个数相加求和

 @param c_num 加数个数
 @param ...   加数

 @return 和
 */
int64_t sum(int c_num, ...) {
    va_list addend_list;
    int64_t sum = 0;

    va_start(addend_list, c_num);

    for (int i = 0; i< c_num; i++) {
        sum += va_arg(addend_list, int);
    }

    va_end(addend_list);

    return sum;
}