Is there a correct place to put javascript within a html file?

[mark4asp]

I ask this because only today I read advice telling me to put it
within the <headelement. This is the same advice I've always been
given but no one ever explained why.

Last week I was told to put it at the bottom of the html just before </
body>; the reason being that html won't start rendering until all the
script files have downloaded and if they're all in the head ... Right
now I'm putting all my javascript at the end of the html file seems
like the sensible thing to do; at least there's a reason for it.

[RobG]

On Oct 20, 2:25 am, mark4asp <[e-mail]:

I ask this

You should not assume that we can see or remember the subject of your
post when reading the body.

because only today I read advice telling me to put it
within the <headelement.

Reasonable advice because that is one place that script elements are
allowed, they are also permitted in the body.

This is the same advice I've always been
given but no one ever explained why.

The HTML specification tells you where script elements are permitted:

<URL: http://www.w3.org/TR/html4/interact/...ml#edef-SCRIPT >

>
Last week I was told to put it at the bottom of the html just before </
body>; the reason being that html won't start rendering until all the
script files have downloaded and if they're all in the head ... Right
now I'm putting all my javascript at the end of the html file seems
like the sensible thing to do; at least there's a reason for it.

You haven't provided any reason at all. Where you place script
elements depends on their intended purpose. There are two guiding
principles:

1. Code should be loaded before there is any chance it might be
called, and

2. If code requires access to DOM elements, it should not be called
before they might exist and should not error if it is.

How you achieve the above is up to you, but the general way is to
achieve the first is to load scripts containing general functions in
the head.

There are a variety of ways to achieve the second - inserting
functions intended to be run when the DOM is ready rather than onload
into a script element just before the closing body tag is one. There
are others, such as using a general "DOM ready" function or waiting
for the load event to occur.
--
Rob

[The Natural Philosopher]

RobG wrote:

On Oct 20, 2:25 am, mark4asp <[e-mail]:

>I ask this

You should not assume that we can see or remember the subject of your
post when reading the body.

>because only today I read advice telling me to put it
within the <headelement.

Reasonable advice because that is one place that script elements are
allowed, they are also permitted in the body.

>This is the same advice I've always been
given but no one ever explained why.

The HTML specification tells you where script elements are permitted:

<URL: http://www.w3.org/TR/html4/interact/...ml#edef-SCRIPT >

Well I read it and it doesn't. It says in the head or the body. What
else is there?

[RobG]

On Oct 20, 11:37 am, The Natural Philosopher <[e-mail]:

RobG wrote:

On Oct 20, 2:25 am, mark4asp <[e-mail]:

I ask this

You should not assume that we can see or remember the subject of your
post when reading the body.

because only today I read advice telling me to put it
within the <headelement.

Reasonable advice because that is one place that script elements are
allowed, they are also permitted in the body.

This is the same advice I've always been
given but no one ever explained why.

The HTML specification tells you where script elements are permitted:

<URL:http://www.w3.org/TR/html4/interact/scripts.html#edef-SCRIPT>

Well I read it and it doesn't.

Yes, it does.

It says in the head or the body.

See?

What else is there?

Life, the universe and everything. :-)
--
Rob

[Dr J R Stockton]

In comp.lang.javascript message <11****************@proxy01.news.clara.n
et>, Sat, 20 Oct 2007 02:37:11, The Natural Philosopher <[e-mail]:

>
Well I read it and it doesn't. It says in the head or the body. What
else is there?

Before the head; between head and body; after the body; inside or
outside the HTML. Before DOCTYPE.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6
news:comp.lang.javascript FAQ <URL:http://www.jibbering.com/faq/index.html>.
<URL:http://www.merlyn.demon.co.uk/js-index.htmjscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/TP/BP/Delphi/jscr/&c, FAQ items, links.

[Dr J R Stockton]

In comp.lang.javascript message <47**************@PointedEars.de>, Mon,
22 Oct 2007 08:44:32, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>Dr J R Stockton wrote:

>[...] The Natural Philosopher <[e-mail]:

>>Well I read it and it doesn't. It says in the head or the body. What
else is there?

Before the head; between head and body; after the body; inside or
outside the HTML. Before DOCTYPE.

>But I don't think the question of the OP was meant as "What other
possibilities are there, generally?"

Then you should learn to understand English, because that is exactly
what he asked for.

--
(c) John Stockton, Surrey, UK. ??*@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/- FAQish topics, acronyms, & links.
Check boilerplate spelling -- error is a public sign of incompetence.
Never fully trust an article from a poster who gives no full real name.

[Dr J R Stockton]

In comp.lang.javascript message <47**************@PointedEars.de>, Tue,
23 Oct 2007 18:57:29, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>Dr J R Stockton wrote:

>In comp.lang.javascript message <47**************@PointedEars.de>, Mon,
22 Oct 2007 08:44:32, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>>Dr J R Stockton wrote:
[...] The Natural Philosopher <[e-mail]:
Well I read it and it doesn't. It says in the head or the body. What
else is there?
Before the head; between head and body; after the body; inside or
outside the HTML. Before DOCTYPE.

>>But I don't think the question of the OP was meant as "What other
possibilities are there, generally?"

Then you should learn to understand English, because that is exactly
what he asked for.

It is not a matter of understanding English or not, but of the capability of
applying common sense which you either lack or have deliberately not used here.

"What else is there?" in this context clearly means "What other valid
possibilities (other than in the `head' or the `body' [element]) are there
to place a HTML `script' element?", and the only good and correct answer
would have been "None."

You, too, should learn to understand English, complete with nuances,
correctly. It's a non-trivial intellectual task, beyond the
capabilities of most non-British.

--
(c) John Stockton, Surrey, UK. ??*@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/- FAQish topics, acronyms, & links.
Check boilerplate spelling -- error is a public sign of incompetence.
Never fully trust an article from a poster who gives no full real name.

[David Cox]

"Dr J R Stockton" <jr*@merlyn.demon.co.ukwrote in message
news:mz**************@invalid.uk.co.demon.merlyn.i nvalid...

In comp.lang.javascript message <47**************@PointedEars.de>, Tue,
23 Oct 2007 18:57:29, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:

>>Dr J R Stockton wrote:

>>In comp.lang.javascript message <47**************@PointedEars.de>, Mon,
22 Oct 2007 08:44:32, Thomas 'PointedEars' Lahn <Po*********@web.de>
posted:
Dr J R Stockton wrote:
[...] The Natural Philosopher <[e-mail]:
>Well I read it and it doesn't. It says in the head or the body. What
>else is there?
Before the head; between head and body; after the body; inside or
outside the HTML. Before DOCTYPE.

But I don't think the question of the OP was meant as "What other
possibilities are there, generally?"

Then you should learn to understand English, because that is exactly
what he asked for.

It is not a matter of understanding English or not, but of the capability
of
applying common sense which you either lack or have deliberately not used
here.

"What else is there?" in this context clearly means "What other valid
possibilities (other than in the `head' or the `body' [element]) are there
to place a HTML `script' element?", and the only good and correct answer
would have been "None."

You, too, should learn to understand English, complete with nuances,
correctly. It's a non-trivial intellectual task, beyond the
capabilities of most non-British.

--
(c) John Stockton, Surrey, UK. ??*@merlyn.demon.co.uk Turnpike v6.05
MIME.
Web <URL:http://www.merlyn.demon.co.uk/- FAQish topics, acronyms, &
links.
Check boilerplate spelling -- error is a public sign of incompetence.
Never fully trust an article from a poster who gives no full real name.

It is beyond the capabilities of most, if not all British, too, English is
too ambiguous.

The classic hand-grenade instructions:
"Pull out the pin and throw it."

[Helpful person]

On Oct 24, 6:40 am, "David Cox" <[e-mail]:

"Dr J R Stockton" <[e-mail] in messagenews:mz**************@invalid.uk.co.demon.m erlyn.invalid...

>
It is beyond the capabilities of most, if not all British, too, English is
too ambiguous.

English is not ambiguous. Its beauty is the difference in nuance
between different words with very similar meanings. That is why it is
such a rich language for good literature.

www.richardfisher.com

[Ivan Marsh]

On Wed, 24 Oct 2007 04:57:30 -0700, Helpful person wrote:

On Oct 24, 6:40 am, "David Cox" <[e-mail]:

>"Dr J R Stockton" <[e-mail] in
messagenews:mz**************@invalid.uk.co.demon. merlyn.invalid...

It is beyond the capabilities of most, if not all British, too, English
is too ambiguous.

English is not ambiguous. Its beauty is the difference in nuance
between different words with very similar meanings. That is why it is
such a rich language for good literature.

The irony is that Thomas is at the top of the list of those who would
point out the minutia of phrasing in a post and drive the subject into the
ground.

--
I told you this was going to happen.

[mark4asp]

On 20 Oct, 02:00, RobG <[e-mail]:

On Oct 20, 2:25 am, mark4asp <[e-mail]:

I ask this

You should not assume that we can see or remember the subject of your
post when reading the body.

because only today I read advice telling me to put it
within the <headelement.

Reasonable advice because that is one place that script elements are
allowed, they are also permitted in the body.

This is the same advice I've always been
given but no one ever explained why.

The HTML specification tells you where script elements are permitted:

<URL:http://www.w3.org/TR/html4/interact/scripts.html#edef-SCRIPT>

Last week I was told to put it at the bottom of the html just before </
body>; the reason being that html won't start rendering until all the
script files have downloaded and if they're all in the head ... Right
now I'm putting all my javascript at the end of the html file seems
like the sensible thing to do; at least there's a reason for it.

You haven't provided any reason at all. Where you place script
elements depends on their intended purpose. There are two guiding
principles:

1. Code should be loaded before there is any chance it might be
called, and

2. If code requires access to DOM elements, it should not be called
before they might exist and should not error if it is.

How you achieve the above is up to you, but the general way is to
achieve the first is to load scripts containing general functions in
the head.

There are a variety of ways to achieve the second - inserting
functions intended to be run when the DOM is ready rather than onload
into a script element just before the closing body tag is one. There
are others, such as using a general "DOM ready" function or waiting
for the load event to occur.

--
Rob

Thanks Rob. In future, I will generally place my script just before
the </bodytag - unless there is a reason not to. Even then it will
be a rare bit of code that is needed in the head element. If all my
javascript is positioned just before the </bodythen the various html
elements must be rendered or in the process of being rendered before
and javascript can run. I don't have much javascript executing on
window.onload but I suppose I could put code in there to check for the
existence of an object before I use it, set and interval and recurse
back?

I'm trying to follow Steven Sounders advice from "High Performance Web
Sites"