/*
    In this example we demonstrate a function with variable number of parameters.
*/

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

/*
    Calculate the sum of variable number of integer parameters.
    Last argument must be zero.
*/

int super_sum(int x,...)
{
    int total = x;
    va_list ap;
    int arg;
    va_start(ap, x);
    while ((arg = va_arg(ap,int)) != 0)
    {
        total += arg;
    }
    va_end(ap);
    return total;
}

/*
    Calculate the sum of variable number of integer parameters.
    We pass the number of parameters as the first function parameter.
*/

int super_sum2(int popularity,int x,...)
{
    int total = x;
    int i;
    va_list ap;
    va_start(ap, x);
    for ( i=1; i<popularity; i++)
    {
        total += va_arg(ap,int);
    }
    va_end(ap);
    return total;
}

int super_max(int x,...)
{
    int max = x;
    va_list ap;
    int arg;
    va_start(ap, x);
    while ((arg = va_arg(ap,int)) != 0)
    {
        if(max<arg)
        {
            max=arg;
        }
    }
    va_end(ap);
    return max;
}

/*
    Print variable number of integer parameters.
    Last parameter must be zero.
*/

void print_ints(int x,...)
{
    va_list ap;
    int arg;
    va_start(ap, x);
    printf("%d ",x);
    while ((arg = va_arg(ap,int)) != 0)
    {
        printf("%d ",arg);
    }
    printf("\n");
    va_end(ap);
}

void main(void)
{
    int sum1=super_sum(10,5,20,40,5,0);
    int sum2=super_sum2(5,10,5,20,40,5);
    int max=super_max(10,5,20,40,5,0);

    printf("\nHere are some numbers :\n\n");
    print_ints(10,5,20,40,5,0);
    printf("\nfirst sum is %d\n",sum1);
    printf("\nsecond sum is %d\n",sum2);
    printf("\nmax is %d\n",max);
    printf("press any key to continue ...\n");

    getch();

    printf("\nHere are some other numbers :\n\n");
    print_ints(12,6,8,7,200,-1,2,3,4,89,7,9,0);
    sum1=super_sum(12,6,8,7,200,-1,2,3,4,89,7,9,0);
    sum2=super_sum2(12,12,6,8,7,200,-1,2,3,4,89,7,9);
    max=super_max(12,6,8,7,200,-1,2,3,4,89,7,9,0);
    printf("\nfirst sum is %d\n",sum1);
    printf("\nsecond sum is %d\n",sum2);
    printf("\nmax is %d\n",max);

    getch();
}

© 2004 Jim Valavanis