Re: [PIC] Learning C

On Wed, 20 Nov 2024, Forrest Christian (List Account) wrote:

> Things got a lot clearer when I finally realized that there is absolutely
> no difference to the compiler between:
>
> x=array[i]
>
> And:
>
> x=*(array+i)
>
> The same is true for a pointer... you can use ptr[i] interchangeably with
> *(ptr+i) .

I concur but this can be confusing for a novice that doesn't understand 
that "i" gets scaled based on the type of array. If you have an array of 
structures this could involve doing a multiply in software.

>
> Once they're defined, the only difference between an array and a pointer is
> that you can't change the address of an array (its determined by the
> compiler), but the address a pointer points at can be changed at will.
>

Actually there is another difference between an array and a pointer: it is 
the same as the difference between a constant and a variable.

try writing some PIC16 assembler to get the value of arr[j] for all four 
cases where arr is defined as a label and also as a pointer ***AND*** 
where j is defined as a constant and as a variable.

Friendly Regards
Sergio Masci