13 Aug
2006
13 Aug
'06
9:43 p.m.
No, they aren't. But I personally never
remembered if C stores
arrays row major, or column major.
I can't either, but that's because I can't recall which way is row
major and which way is column major. But when I recall that
int foo[20];
declares foo to be int[20], and
int bar[10][20];
declares bar[x] to be int[20] ("int (bar[10])[20];") then it all makes
sense.
But really, it gets to me when I see code like:
for (i = 0 ; i < MAX ; i++)
foo[i] = 0;
when it could easily be replaced with:
memset(foo,0,sizeof(foo));
While I realize you said "when", I would point out that this is a valid
replacement only when foo is an integral type. If foo is float or
pointer, this is not a safe thing to do (except in code that's
sufficiently hardware-specific that you can assume the in-memory layout
of the relevant data type - and know that all-0-bits is TRT).
Also, note that this assumes that sizeof(foo) is MAX*sizeof(foo[0]),
though I realize this is easy to fix in the memset call.
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