Why do numbers work, but variables don't in this array?

Ok, here's my dumbdumb question of the day:

I have this loop that's supposed to loop through the 11 XML elements named
"title" in the object.

When I put a number in the array brackets like this:

tables = response.getElementsByTagName("title");

for(var i = 0;i <= tables.length;i++) {
strTitles = strTitles + tables[1].firstChild.nodeValue+"<br/>";
}

document.getElementById('foo').innerHTML = strTitles;

....I get the appropriate value displayed (albeit 11 times).

But when I try to put in the variable "i", like this:

tables = response.getElementsByTagName("title");

for(var i = 0;i <= tables.length;i++) {
strTitles = strTitles + tables[i].firstChild.nodeValue+"<br/>";
}

document.getElementById('foo').innerHTML = strTitles;

....I get the following error:

Error:tables[i] has no properties?

Any clue why? I'm sure when I hear the answer I'll be kicking myself, but
I have to know. :)


--
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Sugapablo -> http://www.sugapablo.net
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re: Why do numbers work, but variables don't in this array?

Sugapablo wrote:

[color=blue]
> for(var i = 0;i <= tables.length;i++) {[/color]

for (var i = 0; i < tables.length; i++) {


--

Martin Honnen
http://JavaScript.FAQTs.com/

re: Why do numbers work, but variables don't in this array?

Sugapablo wrote:[color=blue]
> Ok, here's my dumbdumb question of the day:
>
> I have this loop that's supposed to loop through the
> 11 XML elements named "title" in the object.
>
> When I put a number in the array brackets like this:
>
> tables = response.getElementsByTagName("title");[/color]

So there is no Array involved in this question at all then? The -
getElementsByTagName - method returns an object implementing the -
NodeList - interface.

Incidentally, it is distinctly odd to name a variable "tables" and
assign a reference to a - NodeList - of TITLE elements to that
variable.
[color=blue]
> for(var i = 0;i <= tables.length;i++) {[/color]

You have recognised that javascript tends to use zero-based Arrays,
collections, etc. That is true of the - NodeList - interface as well.
But the - length - property of such objects is the number of elements
they contain and so includes the object at index zero. You should
iterate to - i < tables.length - because there will be no element at
index tables.length.
[color=blue]
> strTitles = strTitles + tables[1].firstChild.nodeValue+"<br/>";
> }
>
> document.getElementById('foo').innerHTML = strTitles;
>
> ...I get the appropriate value displayed (albeit 11 times).[/color]

You have 11 TITLE elements in the same document?
[color=blue]
> But when I try to put in the variable "i", like this:
>
> tables = response.getElementsByTagName("title");
>
> for(var i = 0;i <= tables.length;i++) {
> strTitles = strTitles + tables[i].firstChild.nodeValue+"<br/>";
> }
>
> document.getElementById('foo').innerHTML = strTitles;
>
> ...I get the following error:
>
> Error:tables[i] has no properties?[/color]

When - i - equals the - length - of the - NodeList - there is no element
at - tables[i] -.
[color=blue]
> I'm sure when I hear the answer I'll be kicking myself, ...[/color]

Yes, you will. ;)

Richard.

re: Why do numbers work, but variables don't in this array?

On Fri, 04 Nov 2005 19:17:25 +0000, Richard Cornford wrote:
[color=blue]
> When - i - equals the - length - of the - NodeList - there is no element
> at - tables[i] -.
>[color=green]
>> I'm sure when I hear the answer I'll be kicking myself, ...[/color]
>
> Yes, you will. ;)[/color]

Yes, I am. (*explitive*)

Thanks!


--
[================================================== ===========================]
Sugapablo -> http://www.sugapablo.net
[================================================== ===========================]