hi.i want to save from size.so i want to make the clear function like this:
but it calls the destructor after the constructor again.
also i want to ask why i can't call the destructor with only:
and the constructor with:
thx..

What is your question?

I would not make a habit out of calling destructors like that. What exactly are you trying to accomplish?

Also, in your destructor, you may want to check to make sure that p is not NULL before freeing it.

why don't u use constructors and destructors like that?what is wrong with it?i said in the post,it's for saving from file size.three lines means,a place for one more function and i don't want it.also it could be more lines than three.you may be right about freeing p.

Why are you worried about 3 lines? That is less than 100 bytes. You should be able to find a hard drive that has millions of bytes (some of them have billions). Saving the file size of your source code should not be a high priority in comparison with writing cleaner code.

cleaner code.i was talking about that too.according to you which seems more clear,this one:
or this one:

which is the one that appropriates to less code reuse?
if there's another function that does the same function why do i write it again?

I would probably have done it the opposite way but if that way works for you, more power to you.

The opposite way would be like:

The thing to worry about is if you ever put something in the destructor that you would not want on a regular clear(). I suppose it would work either way.

but it's unnecessary to make p NULL and size=0 for a stack variable that goes out of scope.so it makes the program run slower.i'm wondering one thing.so if the destructor is this:
this function:

prints:

in here:

s.clear();

tell me this if u know?

That is correct. If you call the clear() method it will run the destructor, but then it runs the destructor automatically (that's the purpose of the destructor) when it leaves the scope or is deleted.

Because a destructor is not a global function.

So you would need an object to call the constructor? And to get an object you would need to call the constructor. But you couldn't call the constructor until you had an object. So you could never call the constructor.

I myself kind of missed what was the question in this thread. It was not very clear.

If it's a stack variable, why were you freeing it in the first place?

This thread REALLY confuses me. Could you take some time to state your question clearly if it wasn't already answered.

fakepoo it's not like you think it's not because of the stack variable that goes out of scope,i stopped the program before return 0; with getchar() and look output,there were two "p deleted" lines.it's because,in the clear function.when i call stack() function,immediately after it jumps to destructor again,before the function finishes.i'm trying to understand this.is there a temporary object there?if there is,which object do the p variable that it makes NULL and the size variable that it makes 0 belongs to?if i declare a variable like u do:
stack<int> s;
do they belong to s?or the temporary variable?
can we make calls like this in main?
s=stack();
if we can do;then should i change the stack(); line in the clear function like this:
*this=stack();