In article <19940113173624.vanvalke@rlvan.larc.nasa.gov> vanvalke@sealsun1.larc.nasa.gov (Randal L. VanValkenburg) writes:
>In Article <CJ4Dss.2B3@ennews.eas.asu.edu> "madden@enuxsa.eas.asu.edu (David
Madden)" says:>>
>> When I try to run the following code in IDE by single stepping (F8), the
>> code runs fine.  However, when I try to run the code, the output is as
>> expected, but the execution freezes.  The code is run on Borland C++, ver 3.1.
>>
>> I cannot figure what is wrong...
>>
>> ------------------------------  code  ------------------------------------
>>       BI_IListImp<int> questions; // note: necessary since I will be
>>                                       // adding my own structure as soon
>>                                       // as I get this working right!
>>
>>       int *x, *y, *z;
>>       *x = 3; *y = 4; *z = 5;
>>
>>       questions.add(x);
>>       questions.add(y);
>>       questions.add(z);
>Looks like you are dereferencing 3 uninitialized pointers (x, y, z) and
>then sticking the values 3, 4, 5 into these random memory locations. Why not
>try:
>       int x = 3;
>
>       questions.add(&x);

That's the right problem, but this answer will still leave pointers pointing
at local memory, which will be freed when the routine returns. You need to
allocate memory for x, y, an z to point at using the new operator.

Ralph

In Article <CJ4Dss.2B3@ennews.eas.asu.edu> "madden@enuxsa.eas.asu.edu (David Madden)" says:
>
> When I try to run the following code in IDE by single stepping (F8), the
> code runs fine.  However, when I try to run the code, the output is as
> expected, but the execution freezes.  The code is run on Borland C++, ver 3.1.
>
> I cannot figure what is wrong...
>
> ------------------------------  code  ------------------------------------
>  BI_IListImp<int> questions; // note: necessary since I will be
>      // adding my own structure as soon
>      // as I get this working right!
>
>  int *x, *y, *z;
>  *x = 3; *y = 4; *z = 5;
>
>  questions.add(x);
>  questions.add(y);
>  questions.add(z);
Looks like you are dereferencing 3 uninitialized pointers (x, y, z) and
then sticking the values 3, 4, 5 into these random memory locations. Why not
try:
       int x = 3;

       questions.add(&x);
Randy VanValkenburg
NASA - Langley Research Cent

When I try to run the following code in IDE by single stepping (F8), the
code runs fine.  However, when I try to run the code, the output is as
expected, but the execution freezes.  The code is run on Borland C++, ver 3.1.

I cannot figure what is wrong...

------------------------------  code  ------------------------------------

#include <iostream.h>
#include <iomanip.h>
#include <list.h>
#include <listimp.h>

main()
{
 BI_IListImp<int> questions; // note: necessary since I will be
     // adding my own structure as soon
     // as I get this working right!

 int *x, *y, *z;
 *x = 3; *y = 4; *z = 5;

 questions.add(x);
 questions.add(y);
 questions.add(z);


 BI_IListIteratorImp<int> newlst(questions);

 cout << "--------\n";

 while (newlst) {
  int *temp = newlst.current();
  cout << *temp << "\n";
  newlst++;
 }

return 0;
}

--------------------------  output -------------------------------------

--------
5
4
3

As mentioned, if single stepped via <F8>, the completed execution returns
to the IDE.  However, when trying to run the code, the output is generated
but the program "hangs" indefinitely, and does not return to the IDE.

Please help!

--


======================================================
|  David W. Madden   ||   Arizona State University   |
|  (602) 965-1792    ||   MADDEN@ENUXSA.EAS.ASU.EDU  |
======================================================