//  argumentdemo, muh, 4/2019
//  shows various types of arguments and behavior
#include <stdio.h>

// demo functions here
int demoint (int d) {
  d = d*100;
  return d;
}

int demopointer (int *p) {  // p is a pointer to an int
  *p = *p *10;
  return (*p + 5);  // return an int
}

int morepointer (int *p) {
  int d = *p;   // value located at p
  int *q = &d;  // q is pointer to d
  *p = *q;      // value in p equals value of q
  printf ("Addresses %p (p) and %p (q).\n", p, q);
  printf ("Values of  %d (p) and %d (q).\n", *p, *q);
  *p = *q + 1;
  return *q + 2;
}

int main (int argc, char **argv) {
  int mainint = 3;
  int *mainintptr = &mainint;  // hold address of mainint
  int returnint;


  // test passing just the integer
  returnint = demoint(mainint);
  printf("\ndemoint: mainint=%d, returnint=%d\n", mainint, returnint);

  // test passing a pointer
  returnint = demopointer(mainintptr);
  printf("\ndemopointer: mainint=%d, returnint=%d\n", mainint, returnint);

  // test more complicated pointer
  returnint = morepointer(mainintptr);
  printf("\nmorepointer: mainint=%d, returnint=%d\n\n", mainint, returnint);

  return 0;  // return a value to show we succeeded
}