[NTLUG:Discuss] OT C question

[Spicerun]

If I may (not that I'm some great expert or anything), can I recommend 
that Integers not be directly added to a pointer, but that the pointer 
is incremented or decremented to thr right position?

IE-

Aptr++;
Aptr += 7;
Aptr[7];

Will work (my preferred ways), but

Aptr + 1;
Aptr + 7;

aren't particularly good practice.  Your examples currently work right 
now because Aptr is a char pointer, whose unit size is 1 byte (8 bits), 
but if Aptr was an integer pointer whose unit size was 4 bytes (on an 
x86 processor), you'd be moving the pointer to bytes within your integer 
and not get the results you're looking for.  Incrementing or 
Decrementing the pointer will insure that you really are going to the 
next element of your array rather than a byte inside of your current 
element.

My rule of thumb is to never add Integers to any type of pointers.

Just my $.02

--Spicerun



Paul M Foster wrote:
>
> The printf expressions above should be:
>
> printf("%c\n", *(Aptr + 1));
> printf("%c\n", *(Aptr + 7));
>
> The "contents of" operator (*) binds more tightly than the addition 
> operator (+), so in your code, you're just incrementing the contents 
> of the pointer location, rather than incrementing the pointer.
>