--- In [email protected], "John Matthews" <[EMAIL PROTECTED]> wrote:
>
> --- In [email protected], "raj_duttaphookan"
> <raj_duttaphookan@> wrote:
> >
> > --- In [email protected], "John Matthews" <jm5678@> wrote:
> > >
> > > --- In [email protected], "raj_duttaphookan"
> > > <raj_duttaphookan@> wrote:
> > > >
> > > > Why can't we simply
> > > > define it as a pointer. It shall anyway hold the memory
address
> > and
> > > > later on while dereferencing it, it shall automatically
> > dereference it
> > > > depending on whether the memory address it contained was
that of
> > an
> > > > int or a float or a char etc.
> > >
> > > But when dereferencing, how would the compiler know what was
> > stored in
> > > the memory? It can't just use the destination type. For
example:
> > >
> > > pointer p;
> > > int i;
> > >
> > > i = *p;
> > >
> > > Does the memory pointed to by p contain a 4 byte integer, a 2
byte
> > > integer, or a 1 byte character, all of which can be assigned
to an
> > > integer variable?
> > >
> > I guess the compiler would know it because when we define a
variable
> > it is assigned a memory address.
> > so the compiler already know what is stored at address 10448
and
> > what is stored at address 10566.
>
> But to handle something like:
>
> int getValue(pointer p)
> {
> return *p; // what type?
> }
>
> the compiler would have to maintain a list of all memory addresses
and
> the type of information in them.
>
> John
>
Well, you do have a point, but I am not convienced.
In your above explaination, I guess when the getValue( ) function
shall be called, it shall be something like:
main( )
{
int x;
..............;
..............;
int getValue(&x);//the address of x is passed on to the calling
//function.
..............;
}
int getValue(pointer p) //here the address shall come to p
{
return *p; // here it is simply returning the value at the
//address which is contained in p. And since it
//was already defined in main( ) as int x, so
//obviously it shall return an int.
}
