Earlier quoted context omitted.
At which number starts the first centimeter on a ruler ?
At which number starts the zeroth centimeter on a ruler?
it's the first and it is 0, just like the first index in a C array is 0
Why do arrays start at 0?
301–310 of 702 posts
Re: Why do arrays start at 0?
#302Earlier quoted context omitted.
> when we count, we start at 1, we talk about the "1st" Although often with an implicit zero. Under typical North American culture, your 1st birthday, for example, is more accurately the first anniversary of your birthday. Your birth is zero indexed.
It's fundamentally a distinction between end-index and start-index. Most human counting uses end-index. I.e. "1" is after 1-thing (has passed, is physically obtained, etc.). Most computer counting uses start-index + length, for efficiency and to better generalize. I.e. "1" is at the memory address immediately before the "1"st item. Which ultimately creates the "0 index is 1st thing" linguistic confusion. PS: Also, la…
good take!
i think a more accurate and complete idea is that humans refer to a thing in its entirety, with things being lined up and scanned in order as only a potential convenience
if you ask someone to identify an object, they'll point to the middle (or center of the most important component) of the object, not to the 'start' or 'end' of it in their field of vision..
that said, the human perspective is subtle and convenient in completely different ways to how a computer manages memory, and this 'end-index' idea seems like a useful way to map the human whole-object perspective to a linear memory-index perspective
Re: Why do arrays start at 0?
#303Earlier quoted context omitted.
No. 1. Optimizing compilers exist. 2. Addressing at fixed offsets is cheap (a single instruction): https://en.wikipedia.org/wiki/Addressing_mode 0-based indexing is superior (as a default) because it simplifies a lot of common math, as discussed in TFA.
TFA = Thanks For Asking?
Re: Why do arrays start at 0?
#304Edsger Dijkstra wrote an interesting article titled 'why numbering should start at 0'. Perhaps not answering the question directly but an interesting read nonetheless. https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/E...
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Re: Why do arrays start at 0?
#305I may think that counting 0 as a natural number makes a lot of math more elegant, but clearly I’m just too dumb to rise to the level of wrong.
fruits = ['apple'] \\ Hello I have fruits
x = len(fruits) \\ Only one kind tho lol
fruits[x] \\ OK here is what I have
SUBSCRIPT OUT OF RANGE
Essentially what we have here is a mismatch between the tool (computer that does everything in binary) and the task (mathematical abstraction of quantities). Now it's completely understandable that people work within the limitations of the tool when there is no other choice, but that's the same sort of path dependency that creates technical debt.
If zero indexing were so great, mathematicians would have made it the default centuries if not millennia ago; but mathematicians don't want to do off-by-1 adjustments on all sorts of common operations because it makes things unnecessarily complicated. To be honest, I think this has become a moat to keep people out of programming even though it's a shallow one.
It could be interesting to test this, say by taking two classes of schoolchildren and teaching one Julia and the other Python (or...). By not having to take on the idea of zero-indexing at the same time as the concept of an array, the Julia group can get into collections using their intuitive understanding of the natural numbers. I expect that picking up language elements quickly will have a compounding effect and that at the end of the evaluation period the Julia group will be able to make significantly more complex programs than a control group.
Edit: in your heart you know I'm right
Re: Why do arrays start at 0?
#306Starting at one led to the whole "2000 is not the millennium" thing, as there is no year zero.
Even more painful is that the 2001 began the 21st century, not the 20th.
Re: Why do arrays start at 0?
#307I don't quite understand the argument "0-based being easier for pointer arithmetic is nonsense because the language doesn't have pointers". Whether or not the language presents the concept of "pointer" to the user is independent of whether or not it uses pointers internally. And if it exposes arrays as a concept, it has to implement them somehow. The simplest possible implementation of arrays is having a start addres…
Nats start at 0, end of discussion - it's only logical to index by the naturals.
If there were any justice in the world, they'd start at 2, as a handicap. They might even make it out of the bottom of the NL east if that was the case.
Re: Why do arrays start at 0?
#308Earlier quoted context omitted.
> Birthdays are anniversaries. Indeed they are, which is why I literally said so in the previous comment. Did you forget to finish reading it? > They do not include the event itself. That is true because the event itself is implied information. There is no value in speaking of it. If you stand before us, we can be certain that you had a day of birth (your 0th anniversary). We don't necessarily know how many times you…
If I care about apples (for my lunch, or my store), I care about the difference between having 0 of them and not having bothered to count yet. 0!=null
If no apples is the unusual state, like you expected to find an apple in your lunchbox but someone ate it without your knowledge, then certainly there would be reason to communicate the no apples state. It is ignored in communication when it does not provide useful information, but it is not forgotten. The 0th index is implicitly there.
Re: Why do arrays start at 0?
#309base^0 = 1
base^1 = base
base^2 = base * base
et cetera.
I've always considered the index and the power to which a base has been raised to be equivalent in many circumstances.
Thus starting at 0 makes sense.
Re: Why do arrays start at 0?
#310Earlier quoted context omitted.
It could just as easily be 1 ≤ i ≤ N and then I wouldn't have to remember that the lower bound is inclusive and the upper exclusive.
Then the delta of both bounds (N – 1) wouldn’t equal the length of the range (N). The inclusive-exclusive convention is used in order for `end = start + length` to hold.
Why does that matter when the starting point is 1? In that case, you don't need the delta because you have the length already. In the case of a 0-based range you also don't need the delta, though you will want to use the inclusive-exclusive convention so that you get the length "for free".
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