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Comment by toolslive | Hacker News Reader

> No off-by-one error – By default, Fortran uses a 1-based indexing. No off-by-one errors, period.

I'm with Dijkstra on this one. https://www.cs.utexas.edu/~EWD/transcriptions/EWD08xx/EWD831...

OP here. 0-based vs 1-based indexing is one these hot debates I don't want get in as I've mentioned in the post. Yet, point is, if you take pretty much any math textbook, indexing starts at 1, whether we like it or not. And for many students, understanding the mechanics of a given algorithm is already enough of an effort that they do not need, on top of that, to translate every indices in the book's pseudo-code from 1-based to 0-based. That's all I'm saying. No other value judgement.

Dijkstra is right, of course. However, most math texts still use 1-based indexing. If you want to translate them into code, it's easier when the conventions match.

(Now, if you had a proposal for switching math over to 0-based indexing ...)

Good luck getting a community with literally hundreds of years of literature using 1 based indexing to change.

I did have one or two math professors who would use x_0 and x_1 instead of x_1 and x_2 when they had to name two objects.

But I have also seen places where 1-based indexing was used despite being "obviously wrong". I don't quite recall what it was, but there was sequence of objects A_1, A_2, ... and a natural way of combining A_k and A_l to get A_(k + l - 1). Had the indices been shifted by 1 to be 0-based, the result would have been A_(k + l), which would be much nicer to work with.

He (Dijkstra) even mentions this in the article:

> The above has been triggered by a recent incident, when, in an emotional outburst, one of my mathematical colleagues at the University —not a computing scientist— accused a number of younger computing scientists of "pedantry" because —as they do by habit— they started numbering at zero.

Doesn't fortran also support the ability to define arrays with arbitrary bounds i.e. (-4, 5) which is quite difficult todo in other languages

Yes, but pitfalls were added to the feature in Fortran '90 and it should now be generally avoided.

I strongly disagree. Arbitrary bounds are tremendously helpful in dealing with arrays whose starting point must be offset.

I didn't say that they were not helpful; I said they have dangerous pitfalls. Also, they're not perfectly portable. My testing shows that only two compilers get lower bounds right in all the tricky cases that I know of.

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