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.
--
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[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.