bobtransformer wrote:
> Hi, and thank you for the help on my "expected an expression" problem from
> this weekend. It now works !!
>
> So, I am trying to use memory very sparingly in my embedded system, as I
> always try to do.
>
> I have a char array that is initialized to 128 bytes, say like this...
>
> char myarray[128];
>
> Now, sometimes I want to re-use this array for ints and shorts, and I know
> that it will be good for 64 shorts or 32 int values. I cannot just
> type-cast like this: (int) myarray[2] = 123456; for instance.
>
> What is the best way to use this existing allocated memory for all 3 types of
> data ?? I do not need to convert int data to char or anything like that. I
> just want to use the array for the different types at different times in the
> program. This array is only temporary storage for reading and writing data to
> and from an EEprom.
>
> One method that comes to mind is a union, but I'm not sure if that is the
> best way.
>
> Ideas ??
>
> Thank you again !
> boB
You can reuse the array with typecasting but be sure to very carefully
document it. You could use a pointer like:
int *myarray_as_int = (int *)myarray;
Then access the array with myarray_as_int when you want to store ints.
A union would work as well (and perhaps better as your code might be
more readable):
union {
char as_char[128];
short int[64];
int as_int[32];
} myarray;
myarray.as_int[2];
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