C'mon, guys!

[Stanley Friesen]

In article <769 at aimmi.UUCP> gilbert at aimmi.UUCP (Gilbert Cockton) writes:
>
>Despite reading three years of discussion on and off on the pointer-array
>equivalance topic, as a casual user of C, I've never been able to come
>up with a clear view on when pointers and arrays are equivalent.
>I'm sure much of my confusion has actually been caused by reading the
>news.
>
>Any volunteers for a simple set of statements that get the message
>across? There must be many C compiler experts out there.
>

	OK, I'll try. First statement

 * A two-dimensional array is an array of one-dimensional arrays, and
   multi-dimensioanl arrays are produced by repeating this composition
   process.

>All I can start with is a straw man, as I'm no expert. 
>
>* given an array of dimensions a x b x c .. x n,
>  the array name is a pointer to array[0][0][0]..[0]
>
      * Close, the array name is a *constant* pointer to the first
	b x c x .. x n dimensional *subarray*, i.e. to array[0].

>* the only time this is any real use if when passing arrays by reference
>  as `array' is easier and safer to write than
>
>	  &(array[0][0][0]..[0])
>
>  as you don't need to bear the array dimensions in mind.

      * I would say its real use is to allow writing algorithms which
	may be applied to any one of several similar arrays by using
	a pointer instead of an array and initializing the pointer to
	the first element of the array. (especially since 'array' is
	equivalent to '&(array[0])' rather than the longer form you
	suggest)


	To summarize, given the declaration:

TYPE array[a][b][c]...[n];

	the following two usages are equivalent:
	array		&array[0]
-- 

				Sarima (Stanley Friesen)

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