The importance of showing ALL of the code in C

From: Ram Meenakshisundaram <rmeenaks_at_olf.com>
Date: Wed Feb 6 14:52:26 2002

"Fred Cisin (XenoSoft)" wrote:

> On Wed, 6 Feb 2002, John Chris Wren wrote:
> > Or it would possibly cause a segfault, since A can only be legally indexed
> > by 0..9. (This is assuming it didn't get optimized out).
>
> No. In C, that is actually NOT considered an error by the language! It's
> "bad form", but permitted by the language to use array notation to access
> memory locations that were NOT allocated to the array!

Thats because array notations are nothing more that pointer arithmetics. That is
why it is valid. It eventually becomes *(A + 10) which is *VALID* like any other
pointer operations in C. Of course, this may SEGV in certain systems. I remember
that * (A - 1) used to have the size of the array that was allocated! Dont know if
that
is true today....


Ram

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Received on Wed Feb 06 2002 - 14:52:26 GMT