Re: [Dev-C++] Hello

[Jason H. <jas...@bt...>]

MessageThanks, I wrote about it of the top of my head, but not using =
dynamic allocation of arrays all that often I forgot about the array =
version. Only in recent weeks have I started coding again, so I'll =
admitt I am a bit rusty, but it's just like riding a bike :)

Any more mistakes anyone?

Jason.
  ----- Original Message -----=20
  From: Ioannis Vranos=20
  To: dev...@li...=20
  Sent: Sunday, September 16, 2001 4:03 AM
  Subject: RE: [Dev-C++] Hello


  I write this because you said to point out the mistakes. :)

  It is not new() and delete(), they are operators new and delete ( and =
new[] and delete[]).

  Then in your code you do p=3Dnew int[10] and delete p; but it should =
be delete[] p;

  Also new, new[],  delete and delete[] are better because you can =
define what to do in memory allocation failure of new or new[] using =
set_new_handler() and overiding them to define where to place their =
objects (placement operators) in already allocated memory (even in the =
stack), which is a bit advanced topic.


  Regards,
  Ioannis

  * Ioannis Vranos
  * Programming pages: http://www.noicys.f2s.com
  * Alternative URL: http://run.to/noicys
    -----Original Message-----
    From: dev...@li... =
[mailto:dev...@li...] On Behalf Of Jason =
Hardman
    Sent: Sunday, September 16, 2001 1:42 AM
    To: dev...@li...
    Subject: Re: [Dev-C++] Hello


    I'm afraid I can't offer you much help with OpenGL and those =
tutorials, but I do know something about "free()".

    When programming in C you use free() allong with malloc() to =
dynamically create and *free* up memory. If you want to learn more about =
dynamic allocation you should read a good C/C++ book. Any C book should =
explain more about malloc() and free().

    From what you have said it sounds like you need to include =
<stdlib.h>, which is where those functions are declared. If it is =
already defined then the problem is elsewhere.

    As for alternatives... if you are using C++ (as aposed to pure C) =
then you can use the dynamic allocation functions that are part of the =
C++ language, which are new() and delete(). Again any good C++ book will =
explain these. Using malloc() and free() is still valid in C++ (and you =
can use the header <cstdlib> instead of <stdlib.h>), but new() and =
delete() are better because of the way they are designed to handle =
pointers and datatypes as part of the language.

    i.e.

    int *p;
    p =3D new int[10]; // create an int array

    for(int i=3D0; i<10; ++i)
        p[i] =3D i*i; // fill array with square of 0 through to 9.

    for(int i=3D0; i<10; ++i)
        cout << p[i] << endl; // display contents of dynamic array.
            // don't forget need to include <iostream> to use cout =
etc...

    delete p; // always free up memory or you will get a memory leak!!!
    ...

    This is just a quickie I created off the top of my head, so it =
probably won't work ;-) I'm too lazy to actualy test it.

    p =3D new int[10];

    is the same as

    p =3D (int*) malloc(10*sizeof(int));

    in C.

    delete p;

    is the same as

    free(p);

    in C.

    Just remember you cannot use one malloc() with delete() and new() =
with free().... they don't mix.

    Hope this helps, and anyone else feel free to point out any mistakes =
I may have made.

    Jason.
      ----- Original Message -----=20
      From: Joseph, Brandi, & Elise VanPelt=20
      To: dev...@li...=20
      Sent: Saturday, September 15, 2001 11:38 PM
      Subject: [Dev-C++] Hello


      Hello all,
          This is my first post to this list.  My name is Joseph, you =
can call me Blumojo (or "blu" or "mojo" for short).  I really like =
Dev-cpp and am thinking of sending a donation if I can get the following =
to work.  I am working on NeHe's OpenGL tutorials =
(http://nehe.gamedev.net/)  which are really good - even for a novice =
like me, but the code he gave was for Visual CPP.  I have worked through =
a couple of the problems, but have become "stumped" on lesson 7 where =
the compiler has given me:
      "implicit declaration of function int free()"
      In his explanation, this function is used to free memory used to =
store texture data.

          First of all, has anyone worked through these tutorials and =
ported them to Dev-CPP/MinGW?  If so, I would greatly appreciate the =
code to help me along.  Second, is there another (perhaps better) way to =
free this memory?

      Thank you all so much for the help!

      -Bumojo