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#include <stdio.h>
#include <stdarg.h>
double add(int num_args, ...)
{
va_list my_list;
double i = 0, sum = 0;
va_start(my_list, num_args);
for (i = 0; i < num_args; ++i) {
printf("%lf\n",sum += va_arg(my_list, int)); //everytime the va_arg (function?, macro?) is called it grabs the next argument in the list, but it is not smart enough to figure out if it has gone past the last argument
}
va_end(my_list);
return sum;
}
int main(void)
{
int a = 6, b = 3, c = 1, d = 4, e = 2;
double sum;
sum = add(5,a,b,c,d,e);
printf("main function end: %lf\n",sum);
printf("Printf using %%d, with the second paramater being 22 and the third being a+1 which would be 7. \n%d\n",22,a+1);
printf("The WARNING message given to me by my clang apple compiler (BUT NOT AN ERROR):\nvariable_argument_functions2.c:32:116: warning: data argument not used by format string [-Wformat-extra-args]\n");
//I included the above printf to show that at least with my compiler and most others that this code is valid and will compile.
//While this code does throw warnings, there is no error and the program runs as if the 23 was not there.
//the reason for it not throwing any errors is because there is no implementation defined behavior for what were to happen if more arguments are passed
//the operation expression still occurs, but the printf does nothing else with it
return 0;
}
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