Why $i ?

[mike]

I see people using $i alot, is there something special about it? why not use
$z or $a

[Ewoud Dronkert]

On Fri, 18 Mar 2005 17:38:43 -0000, mike wrote:

I see people using $i alot, is there something special about it? why not use
$z or $a

"i" has always been the first variable name of choice for _i_teration or
_i_ndexing.
--
Firefox Web Browser - Rediscover the web - http://getffox.com/
Thunderbird E-mail and Newsgroups - http://gettbird.com/

[Daniel Tryba]

mike <mi*@localhost.com> wrote:

I see people using $i alot, is there something special about it? why not use
$z or $a

$i(int(eger))

[Warren Oates]

On Fri, 18 Mar 2005 17:38:43 -0000
"mike" <mi*@localhost.com> wrote:

:I see people using $i alot, is there something special about it? why not use
:$z or $a
:
:

I think it originally stood for "integer." Why foo.bar?

--
Looks like more of Texas to Me

[Alvaro G Vicario]

*** mike wrote/escribió (Fri, 18 Mar 2005 17:38:43 -0000):

I see people using $i alot, is there something special about it? why not use
$z or $a

In mathematics it's typical to use i for index variables. When you need
more, you follow the alphabet: i, j, k...

Constants are represented by: a, b, c...

Variables are: x, y, z...
--
-- Álvaro G. Vicario - Burgos, Spain
-- Don't e-mail me your questions, post them to the group
--

[Chris Hope]

Warren Oates wrote:

On Fri, 18 Mar 2005 17:38:43 -0000
"mike" <mi*@localhost.com> wrote:

:I see people using $i alot, is there something special about it? why
:not use $z or $a

I think it originally stood for "integer." Why foo.bar?

Not really an explanation of foobar but somewhat interesting:
http://en.wikipedia.org/wiki/Foo
http://catb.org/~esr/jargon/html/F/foo.html

--
Chris Hope - The Electric Toolbox - http://www.electrictoolbox.com/

[TekWiz]

mike wrote:

I see people using $i alot, is there something special about it? why not use
$z or $a

It's goes back to the basis of programming: Calculus.

In the "Sigma" (Summation) notation, the standard "integer variable" is
normally denoted by "i" or some variable with a subscript "i"; however,
most younger people now use the variable "n".

So it's just as appropriate to use $n as opposed to $i. It's just
preference: 'I'nteger or i'N'teger

--TekWiz

[TekWiz]

Warren Oates wrote:

On Fri, 18 Mar 2005 17:38:43 -0000
"mike" <mi*@localhost.com> wrote:

:I see people using $i alot, is there something special about it? why not use
:$z or $a
:
:

I think it originally stood for "integer." Why foo.bar?

The New Hacker's Dictionary: 3rd Ed. Compiled by Eric S. Raymond says this:

The term "foo" has it's American English roots in WWII Army slang:
"FUBAR" ("Fucked Up Beyond All Repair") which hackers later bowdlerized
into "foobar"

However, it can be traced even further back to the Yiddish word "feh"
and/or English "fooey."

This is the definition that it gives.

"foo /foo/ 1. interj. Term of disgust. 2. Used very generally as a
sample name for absolutely anything, esp. programs and files (esp.
scratch files). 3. First on the standard list of metasyntactic
variables used in syntax examples."

--TekWiz

[NC]

mike wrote:

I see people using $i alot, is there something special about it?

Yes, there is. Tradition. If a mathematician wanted to write
"the sum of first five numbers in sequence X", he would write
something like:

5
Sigma (Xi)
i=1

Obviously, "Sigma" would be a capital-case Greek letter and
the "i" in "Xi" would be a subscript...

Quite a few of early programmers were in fact mathematicians,
so they brought over the tradition of "i" (and "j" for two-
dimensional problems, and "k" for three-dimensional ones)
being a cycle variable.

Cheers,
NC

[Steve]

mike wrote:

I see people using $i alot, is there something special about it? why not use
$z or $a

Historical. In fortran, by default, variables starting with i, j, k and
l ( and maybe more, I forget now ) were integers.

[Gordon Burditt]

>> I see people using $i alot, is there something special about it? why not use

$z or $a

Historical. In fortran, by default, variables starting with i, j, k and
l ( and maybe more, I forget now ) were integers.

FORTRAN had integer variables by default beginning with I, J, K,
L, M, or N. Variables beginning with other letters were real by
default. You could declare the type explicitly.

I believe the mathematical usage of indexes such as i, j, and k far
predates FORTRAN or any other computer language.

Gordon L. Burditt

[Bert Melis]

mike wrote:

I see people using $i alot, is there something special about it? why not use
$z or $a

Because $i stands for "Incredible fast code"

[Chung Leong]

"mike" <mi*@localhost.com> wrote in message
news:d1**********@news7.svr.pol.co.uk...

I see people using $i alot, is there something special about it? why not use $z or $a

Because most programmers are right-handed?

[Jerry Stuckle]

Warren Oates wrote:

On Fri, 18 Mar 2005 17:38:43 -0000
"mike" <mi*@localhost.com> wrote:

:I see people using $i alot, is there something special about it? why not use
:$z or $a
:
:

I think it originally stood for "integer." Why foo.bar?

--
Looks like more of Texas to Me

Close.

It originated back in the 60's with FORTRAN, where the default integers
variable names started with I through N (I think). All others were by
default real (floating point) values.

So, FORTRAN programmers would use I, J, K, etc. as loop counters. And
as they moved into other languages, they just kept using them.

The first reference to foo and bar I know of was in the original IBM PC
DOS 1.0 documentation, where they were used in various examples.
Someone had a good sense of humor (at IBM? naw... :-) ). It was taken
from the old military acronym FUBAR, meaning Fouled (or a less family
oriented word...) Up Beyond All Recognition. This, BTW, was the
superlative. Others were SNAFU (Situation Normal, All Fouled Up) and
TARFU (Things Are Really Fouled Up).
--

To reply, delete the 'x' from my email
Jerry Stuckle,
JDS Computer Training Corp.
js*******@attglobal.net
Member of Independent Computer Consultants Association - www.icca.org

[Kristian Köhntopp]

Jerry Stuckle wrote:

It originated back in the 60's with FORTRAN, where the default integers
variable names started with I through N (I think). All others were by
default real (floating point) values.

Hence the old saying

GOD IS REAL UNLESS DECLARED INTEGER.

Only valid in all caps. :)

Kristian

[Jeb Hunter]

Thus FORTRAN was coined as an acronym for FORmula TRANslation.

--

"Gordon Burditt" <go****@hammy.burditt.org> wrote in message
news:42**********************@news.airnews.net...

I see people using $i alot, is there something special about it? why not use $z or $a

Historical. In fortran, by default, variables starting with i, j, k and
l ( and maybe more, I forget now ) were integers.

FORTRAN had integer variables by default beginning with I, J, K,
L, M, or N. Variables beginning with other letters were real by
default. You could declare the type explicitly.

I believe the mathematical usage of indexes such as i, j, and k far
predates FORTRAN or any other computer language.

Gordon L. Burditt

[George Jempty]

> It's goes back to the basis of programming: Calculus.

In the "Sigma" (Summation) notation, the standard "integer variable" is normally denoted by "i" or some variable with a subscript "i"; however, most younger people now use the variable "n".

So it's just as appropriate to use $n as opposed to $i. It's just
preference: 'I'nteger or i'N'teger

Actually, regarding the context in which one usually finds $i used, a
for loop....

I prefer $n to hold the bound value. Such as

for ($i=0, $n=count($arr); $i<$n; $i++) ....

This performs better than the second clause being "$i < count($arr)" as
the count() function only needs to be invoked once, rather than once
for every time through the loop. All in the spirit of "there's more
than one way...." (and just to head off any follow ups such as "just
use foreach....", sometimes you want to use a for loop, such as when
you might need to retain the value of $i at the point at which you
break out of the loop for some reason or other)

[Jerry Stuckle]

Kristian Köhntopp wrote:

Jerry Stuckle wrote:

It originated back in the 60's with FORTRAN, where the default integers
variable names started with I through N (I think). All others were by
default real (floating point) values.

Hence the old saying

GOD IS REAL UNLESS DECLARED INTEGER.

Only valid in all caps. :)

Kristian

It's been a long time since I heard that one! Thanks for the memories! :-)