RE: Pointer Question

[Jim Langston <jlangston@xxxxxxxxxxx>]

If you are dynamically allocating elements, you shouldn't have to clear them
(as Dan Bale - not Dale states).

There are generally 2 ways to deal with this.  The first way is to keep a
counter with the actual number of active elements.  So if you are only using
8 out of this 1000 elements, you would only iterate (for loop) through those
8, never even looking at the other 9992 records so you don't' care what they
contain.

Another way is to load an all 9's type value into the element past the one
you are actively using so you know it's the end, an EOF (EOE?) marker if you
will.  If you have a text field in the structure, I would load something
like '*** END ***'.

The counter method is the preferred method, I believe, as all 9's can
sometimes be valid data.

Dynamic memory allocation can get pretty tricky and there are a lot of
maintenance issues in your program you are going to have to deal with so you
don't get weird errors and buffer overflows.  If you can do what you want
without dynamic memory allocation you should use some other method (as Hans
stated).

Issues you want to be sure to look at:
1. Make sure you don't try to allocate a 1001's element in a 1000 dimed
array.
2. Make sure that elements you are looking at have been allocated.
3. Make sure that elements you are looking at have been initialized.
4. Make sure that you deallocate elements when you are done with them.
5. Make sure you have some method to detect an out of memory type error.

HTH,

Regards,

Jim Langston

-----Original Message-----
From: Smith, Nelson [mailto:NSmith@lincare.com]

So what is the best way to clear previously used occurrances?  Do I have to
loop through all of them clearing them one at at time?

Further debugging did prove that after using 8 occurs, then resetting the
MODS to use 1 byte, then starting over and reallocating one occurrance's
worth of memory at a time, on the fifth occurrance, I began picking up
previously loaded data. So, apparently, REALLOC does not clear the new
memory it is allocating.  At least not if it has been used previously in the
same job?