same code, different result?!

ok, these are the two sets of code:

Code:

---

if(7500 - (GetTickCount() - timeCreated) <= 0)
    return false;
else
    return true;

---

Code:

---

int x = GetTickCount();
x -= timeCreated;

if(7500 - (x) <= 0)
    return false;
else
    return true;

---

I'm using it as a sort of timer for when to make rockets disappear - each gets called like this, inside of a loop. If it returns false, the rocket disappears ("rockets" is a std::vector):

Code:

---

for(int i = 0; i < rockets.size(); ++i)
{
if(!rockets[ i]->move())
    (...);
}

---

The only problem is, with the first set of code, only one rocket disappears after the designated 7.5 seconds; the rest keep going - but with the second set, they do all disappear after 7.5 seconds! Does anybody know why? :confused:

>if(7500 - (GetTickCount() - timeCreated) <= 0)

GetTickCount() returns a DWORD, which I think is an unsigned long value. So the result of the subtraction is unsigned, so the result is alway > 0.

Try either:
if ((long) 7500 - (long)(GetTickCount() - timeCreated) <= 0)

Or:
if (GetTickCount() - timeCreated >= 7500)

Also, timeCreated should be declared as:

DWORD timeCreated;

Ok, thanks!