different pointer changes in same code
Hi,
My problem is like the below code. In "pushes" function "ptr++" is increasing 16 bytes
and in "pops" "ptr--" code decreasing only 1 byte as normal. I didnt understand the 16.
Why 16 and 1?
(BC++ 5.5)
Code:
#include<iostream.h>
#include<stdlib.h>
#include<string.h>
#include <stdio.h>
class stack{
public:
stack();
~stack();
void pushes(char kr);
void pops();
private:
char* ptr;
int tos;
};
stack::stack()
{
tos = 0;
ptr = (char*) malloc(sizeof(char));
if (!ptr)
{
cout << "alloc err\n";
exit(1);
}
}
stack::~stack()
{
free(ptr);
}
void stack::pushes(char kr)
{
ptr = (char*) malloc(sizeof(char));
if (!ptr)
{
cout << "alloc err\n";
exit(1);
}
*ptr = kr;
tos++;
ptr++;
// printf("%d\n",ptr);
}
void stack::pops()
{
if (tos == 0)
{
cout << "stack empty\n";
return;
}
tos--;
// printf(" - %d\n",ptr);
cout << "pushed [" << tos << "] :" << *ptr << endl;
ptr-= 16;
}
int main()
{
int i;
stack pushpop;
pushpop.pushes('A');
pushpop.pushes('B');
pushpop.pushes('C');
for (i = 0; i < 3; i++)
{
pushpop.pops();
}
return 0;
}
