Pascal's arrays start at 1, at least by default.
Pretty much all variants of BASIC have arrays starting at 1.
Why do arrays start at 0?
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Re: Why do arrays start at 0?
#12> The usual arguments involving pointer arithmetic
Yeah, I think this exactly why it is zero based. The index became a simple multiplier for sizeof(int).
Re: Why do arrays start at 0?
#13I'd claim intuitively that having all bits 0 is a proper starting point and more efficient if there were any constraints on address, which was likely the case historically.
I'm happy to hear any dissenting opinions if this is inaccurate.
Re: Why do arrays start at 0?
#14It really comes down to a choice between a machine-focused (0) or human-focused (1) approach.
The 0 makes a lot of sense in a C pointer world where memcpy and other alike functions can be written very thight.
The 1 makes a lot of sense in a human world, when we count, we start at 1, we talk about the "1st", counting on finger starts with 1, etc.
I once were at a Lua (1 indexed language) conference where this was discussed, and Luis started explaining why Lua was 1-index with this sentence: "The 1st argument ...." :)
Re: Why do arrays start at 0?
#15I have always assumed that is just one less operation required to resolve the absolute memory address.
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.
3. Less buggy for small systems since the Base Pointer address points directly to a record.
4. Macro expansion is often used to store indexes and other 'magic numbers' in Assembler, and this pattern originated either when Assembly was the primary programming language, or even earlier when humans directly punched out cards with machine instructions. Compilers in any remote sense of the luxury we have today did not exist or were not common.
Re: Why do arrays start at 0?
#16Pascal's arrays start at 1, at least by default.
Pretty much all variants of BASIC have arrays starting at 1.
I think a language needs to decide if it is "high level" or if it is instead a convenience language on top of assembly.
BASIC and Pascal I am sure would have been considered a high-level language in their day and naturally would have arrays be 1-based.
C on the other hand....
Re: Why do arrays start at 0?
#17Arrays start at 0 because they're really just pointers. "[x]" is just shorthand for "+ x * sizeof". The first element is the one stored at the pointer address (0 sizeofs ahead of the pointer, the next element is stored 1 sizeof ahead of the pointer, etc.
That answers something like "what are the technical benefits to zero-based arrays" but not "why are zero-based arrays such a strong convention in programming languages." For that you'd have to read the article I guess.
Or it could be:
"technical benefits to zero-based arrays" -> "why zero-based arrays are a strong convention"
Article mentions that Hoye says as much but is dismissive of it. I am not sure why he would be so quick to dismiss.
Re: Why do arrays start at 0?
#18It really comes down to a choice between a machine-focused (0) or human-focused (1) approach. The 0 makes a lot of sense in a C pointer world where memcpy and other alike functions can be written very thight. The 1 makes a lot of sense in a human world, when we count, we start at 1, we talk about the "1st", counting on finger starts with 1, etc. I once were at a Lua (1 indexed language) conference where this was disc…
I don't think 1-based arrays are better notation, even completely ignoring that code has to run on a machine.
99% of the times, the correct approach is to use iterators. When you really need indices (and you almost never do), 0 is more practical, because it matches the "including start, not including end" convention.
Re: Why do arrays start at 0?
#19It really comes down to a choice between a machine-focused (0) or human-focused (1) approach. The 0 makes a lot of sense in a C pointer world where memcpy and other alike functions can be written very thight. The 1 makes a lot of sense in a human world, when we count, we start at 1, we talk about the "1st", counting on finger starts with 1, etc. I once were at a Lua (1 indexed language) conference where this was disc…
> 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.
Re: Why do arrays start at 0?
#20I found it interesting that the author phrased their critique so definitely, i.e. "it's NOT this and NOT that", yet concluded the article by saying their whole argument was speculative. That said, I do agree with their premise that it's going to be pretty tough to get a definitive answer as to why 0-indexing won out. And their criticism of others being so ready to declare results is apt, if not a little ironic in thi…
> yet concluded the article by saying their whole argument was speculative
It's possible to have a speculative argument and also refute other arguments that claim certainty. Pointing out another answer as being wrong does not mean one needs to know the correct answer or claim to have a precise answer.