Re: delete a pointer

It is not required. But the value of pointer is unpredictable then.

So for example if the pointer "a" was pointing to address 12345678 after
deleting it, it will deallocate memory used by the object it was pointing to
but the "a" may still hold a value of 12345678. (I say "may" because your
compiler may automatically reset it to 0 after your "delete").

The same as if you initialize a variable:

int a;

if you read a - it may hold 0 (for my compiler), but for yours it may be
some random value (whatever was stored in that part of memory).

The point is that you cannot count if that pointer will have a certain value
unless you set it again. You shouldn't use "a" after deleting it anyway
without assigning it with new value so in this case if your code is
something like:

function DoStuff()
{
int *a = new Object();

a->DoSomething();

delete a;
a = null;
}

in this case, setting a to null is completely redundant and unnecessary
because when the function ends "a" loses the scope anyway!

But I have a suggestion - rather than using delete, adopt using
std::auto_ptr - the same code looks like this then:

#include <memory>
function DoStuff()
{
std::auto_ptr <int> a(new Object);
a->DoSomething();
}

It takes some getting used to, but generally, much cleaner and no need to
worry about deleting an object.

As far as I know, auto_ptr has no performance penalties and is so much more
convenient to use. On the other hand smart pointers may have some
performance penalties.