C arrays and pointers

[Mark Galassi]

In article <459 at rtech.UUCP> jas at rtech.UUCP (Jim Shankland) writes:
>> array==pointer ... is only true when "array" is being passed
>> or received as a parameter.

>...  "a[b]" is completely, syntactically, semantically,
>and rigorously IDENTICAL to "*(a+b)" (except, again, in an actual declaration).
>Of course, for the above to make sense, one of the operands must be a
>pointer to something, and the other an integral type; but it doesn't matter
>which is which.  It follows that "a[b]" is equivalent to "b[a]" -- a
>notion that most people will not accept without a little head-scratching.
>Jim Shankland

    I don't agree with you: *(a+b) is incorrect, and will not
pass lint's checking. Whay you want is *a + b, and the compiler will scale
b so that if a points to a 16-bit quantity, you will get *(a + 2b) and
so on. I also would like to see an example of your a[b] and b[a]: indexing
an array by pointers is strange, because the pointer b in a[b] would
have a value like 10 or 54 or something that makes sense in your array.
But then taking b[], you might access very weird machine locations.
					Mark Galassi
				...!tektronix!reed!rosalia