RE: [Dev-C++] Correct use of pointers

[Ioannis V. <iv...@in...>]

-----------------------Original Message-----------------------
>From:  Andr=E9 Mac=E1rio Barros [mailto:and...@su...]
>To:  Dev-Cpp-Users [mailto:dev...@li...]
>Date:  14/3/2003 3:31:00 =F0=EC
>Subject:  [Dev-C++] Correct use of pointers
>
>Gentlemen,
>
>   Even in the Ritchie=B4s books sometimes I fount .C codes using "wild
>pointers" or something
>like:
>****************
>void main()

=20
int main()


>{
>   int *p, a, b;
>
>   a=3D2;
>   b=3D3;
>   *p =3D a + b;
>
>   ...
>}
>****************



The above is a mistake. I do not recall something like that in K&R2. Are
you sure it is not written something like this?:


int p[10], a, b;

a=3D2;

b=3D3;

*p=3Da+b;








>But... in large programs we can have problems.
>
>   Would I be corret, allways, if I use insted a code like:
>*********************
>#include <stdlib.h> /* or alloc.h */
>
>void main()
>{
>   int *p, a, b;
>
>   p=3Dmalloc(1*sizeof(int));
>   a=3D2;
>   b=3D3;
>   *p =3D a + b;
>   ...
>   free(p);
>}
>******************
>1. It=B4s not necessary, but is it tecnically correct?



It is correct and required. malloc() could be used like this:


p=3Dmalloc(sizeof(int));


or

p=3Dmalloc(sizeof(*p));



>2. Is there any point, where the previous memory allocation is mandatory=
?

=20

ALWAYS.


Ioannis Vranos=20

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