#include <stdio.h>

struct BankAccount
{
   int    accNum;
   double balance;
};
 
void Add1toBalance( struct BankAccount *p )
{
   p->balance = p->balance + 1;   // p->balance is same as: (*p).balance
}
 
int main(int argc, char *argv[])
{
   struct BankAccount a;
 
   a.accNum  = 123;
   a.balance = 1000.0;
 
   printf("Before calling update: a.accNum = %d  a.balance = %f\n",
		 a.accNum, a.balance);
 
   Add1toBalance( &a ); 
	// Pass the ADDRESS of the struct variable !
 
   printf("AFTER  calling update: a.accNum = %d  a.balance = %f\n",
		 a.accNum, a.balance);
}