Re^4: Use Hash? Array? Still confused after all these years.

I don't say "non negative numbers" either, because you can't use most "non negative numbers" for array indices. I say "counting numbers", "whole numbers", or "cardinal numbers" depending on my mood. It's not really a teaching preference so much as accurately describing the concept.

--
brian d foy <brian@stonehenge.com>

Comment on Re^4: Use Hash? Array? Still confused after all these years.

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Re^5: Use Hash? Array? Still confused after all these years. by exussum0 (Vicar) on Jul 22, 2005 at 11:41 UTC
Which non negative numbers aren't usable? ---- Give me strength for today.. I will not talk it away.. Just for a moment.. It will burn through the clouds.. and shine down on me.	[reply]
Re^6: Use Hash? Array? Still confused after all these years. by willyyam (Priest) on Jul 22, 2005 at 12:58 UTC
Pi? 0.06? Rational numbers (negative or not) are not usable array indices.	[reply]
Re: Use Hash? Array? Still confused after all these years. by benizi (Hermit) on Jul 22, 2005 at 14:29 UTC
I hate to nitpick, because I agree that "non negative numbers" is certainly technically imprecise, and "non negative integers" is overly verbose (an entire extra word! gasp), compared to "whole numbers". (Incidentally, "counting numbers" doesn't include zero.) But, check this out: `perl -Mstrict -lwe 'my @a = (0..20); print $a[$_] for 3.14159, 0.06, ( +75/9), (-75/9)' 3 0 8 13` [download] Perl seems to be doing an implicit 'int' on the index. (Anyone with better understanding of internals know where this happens? I tried creating a simple Tied class, and the FETCH func still sees a whole number.) This allows you to write `$array[rand @array]` rather than `$array[int rand @array]`, for example.	[reply] [d/l] [select]
Re^7: Use Hash? Array? Still confused after all these years. by Anonymous Monk on Jul 22, 2005 at 14:16 UTC
Sort of. `$array[0.06] = 4;` [download] is fine with Perl. Just don't expect it to be different from `$array[1/4]`!	[reply] [d/l] [select]


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