for(int i=0; i<size; i++)

[R Giskard Reventlov]

I now use 'loop' as it is easier to read the code though I did use i for many years just because it was the convention.

"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair. nils illegitimus carborundum me, me, me

[AspDotNetDev]

We programmers are a self-centered bunch. It's never about the other person, it's always "I I I" this, "I I I" that. jk, jk. lol. Hmmm... I suppose the letters in preference would have to be: ijklo. An expanding counter-clockwise spiral starting with "i"! From this, we can ascertain the correct letters to use for each new level of loop nesting: ijklouhmpygntfbrdvescwaxqz. Any other order is incorrect.

Thou mewling ill-breeding pignut!

[PIEBALDconsult]

But "loop" is a verb. :~

[H Brydon]

Look at any mathematics text that is older than computers. You will find i, j, k, m, n rampant as indexes for just about any formula you can find. Also, x, y, z are common variables and A, B, C are commonly used as constants.

-- Harvey

[Rosenne]

AFAIK it started with the first FORTRAN - there were no type declarations then. See https://en.wikipedia.org/wiki/Fortran#FORTRAN[^]

[Jacquers]

As someone already stated, I think it's i for iterator / index. But it also makes it easy to accidentally place a 1 in there e.g. dataset.Tables[1] and not spot a mistake. Sometimes I'll use r and c if iterating through rows and columns e.g. dataset.tables[0].rows[r][c]

[Brady Kelly]

And, mainly, all the CS textbooks use i and j for loops.

[Brady Kelly]

Oi vey, us oldies that have worked with paper tape. I've never used it in programming, but way back, when I was in the SA Air Force, I used to man a station that relayed HF radio data from Antarctica to the SA weather bureau. My main comms with down south was a teletype machine at 50 baud after error correction through a (I think Siemens) Elmux machine. If the comms were bad and the data link failed, they'd send the weather data straight to me, to capture on paper tape and later relay to the weather people.

[Brady Kelly]

But I shudder to think why someone would venture right across the keyboard for a '1' instead of an 'i'. Yes, dataset.Tables[1] will work, but why, oh the humanity, why, are you not using the table name?

[YDaoust]

I tend to use Index instead of i (I definitely like verbose identifiers). And when I need several indexes, like in nested loops, I naturally call them Jndex, Kndex, Lndex... (not kidding). I have not yet come to the point that I use Number and Mumber for counts.

[greldak]

There were but they were implicit. Any variable name beginning with a letter between (and including) the first two letters of INteger was an integer, any other variable was a real.

[Matthew Bache]

If it wasn't for our coding standard, I would employ index, jndex... today. I like that idea.

Matt

[Jacquers]

It could happen during testing, but I agree that using the table name is better.

[gholamali Hosseini]

i am using 'i' and 'j' for iterating 2D arrays because 'i' and 'j' mean x and y in Cartesian coordinates. :) http://butterfly.blog.ir[^]

[YDaoust]

You can use it undercover by means of a macro #define i index ;-)

[YDaoust]

Don't they mean 'horizontal' and 'vertical' ?

[jsc42]

If you were using 'i' before being introduced to FORTRAN, you must have been late being introduced. When I started, there was no lowercase! After some assemblers, FORTRAN IV (aka FORTRAN 66) was one of the first high level languages that I learnt and so I (like everybody else) used I, J, and K as loop variable names. I also used FORTRAN II at college. Shouldn't for(int i =0; i

[gholamali Hosseini]

maybe but I don't think so. horizontal -> h not 'i' & vertical ->v not 'j' the 'i' and 'j' are symbols for horizontal and vertical vectors.

[YDaoust]

probably i -> row and j -> column then

[gholamali Hosseini]

:omg: Hmmmmm...