[EMAIL PROTECTED] wrote:
>
> In C pointers and indexes are different ways
> >to get at, peek into, observe, manipulate, or eavesdrop on, the
> Nevertheless it would not be a good idea for a C programmer to
> confuse an index with a pointer, nor would it be advisable for
> someone, who wants to provide a conceptual theory of C, to confuse
> pointers with indexes.
>
It would not be a good idea for a C programmer (or someone who wants
to provide a conceptual theory of C) to remain ignorant of the fact
that -- beneath the surface -- indexes and pointers are merely
different means of dealing with the same underlying concept.
"Rather more surprising, at least at first sight, is the fact
that a reference to a[i] can also be written as *(a+i). In
evaluating a[i], C converts it to *(a+i) immediately; the two
forms are completely equivalent. Applying the operator & to
both parts of this equivalence, it follows that &a[i] and a+i
are also identical: a+i is the address of the i-th element
beyond a. As the other side of this coin, if pa is a pointer,
expressions may use it with a subscript: pa[i] is identical to
*(pa+i). In short, any array and index expression can be
written as a pointer and offset, and vice versa, even in the
same statement."
_The_C_Programming_Language_, B. Kernighan and D. Ritchie
page 94
-jn-
