Input Arrays

[Nicko]

Hello all,

I'm not sure if this has been posted about recently but I'm very curious
regarding a problem I came across today that I couldn't solve without
PHP. I'd like to use JavaScript because it's for an extranet application
(using IE6) that requires JavaScript anyway, so why not use it?

Anyway, I have a few inputs in an array like so:

<input name="inputArray[]" value="3">
<input name="inputArray[]" value="5">
<input name="inputArray[]" value="4">

Basically, I'd like to use JavaScript to add up all these values and get
the result (in this case, "12"). Is this possible? I tried a few
different ways but none of them worked. Do these arrays work for the id
attribute also (eg. id="inputArray[]")? If so, could I use a
getElementById("inputArray") call or something?

Thanks in advance,

Nicko.

[web.dev]

Nicko wrote:

Hello all,

I'm not sure if this has been posted about recently but I'm very curious
regarding a problem I came across today that I couldn't solve without
PHP. I'd like to use JavaScript because it's for an extranet application
(using IE6) that requires JavaScript anyway, so why not use it?

Anyway, I have a few inputs in an array like so:

<input name="inputArray[]" value="3">
<input name="inputArray[]" value="5">
<input name="inputArray[]" value="4">
Hi Nicko,

First of all, you should know that these are not really arrays. It is
simply a name identifier for that particular object.
Basically, I'd like to use JavaScript to add up all these values and get
the result (in this case, "12"). Is this possible? I tried a few
different ways but none of them worked. Do these arrays work for the id
attribute also (eg. id="inputArray[]")? If so, could I use a
getElementById("inputArray") call or something?

Thanks in advance,

Nicko.

To do this work in the easiest way without rewriting your code, you can
grab your input as a collection and then sum them up like the
following:

var arr = document.getElementsByName("inputArray[]");
var arr_length = arr.length;
var sum = 0;

for(var i = 0; i < arr_length; ++i)
{
sum += parseInt(arr[i].value);
}

Hope this helps. :)

[Nigel Molesworth]

On Fri, 19 Aug 2005 16:06:52 GMT, Nicko wrote:

I'd like to use JavaScript to add up all these values and get
the result (in this case, "12")

Did you get "354"?

If so, you need to convert to a number with parseFloat()

--
Nigel M

[Dr John Stockton]

JRS: In article <2b********************************@4ax.com>, dated
Fri, 19 Aug 2005 17:50:25, seen in news:comp.lang.javascript, Nigel
Molesworth <re***@thegroup.com> posted :

On Fri, 19 Aug 2005 16:06:52 GMT, Nicko wrote:

I'd like to use JavaScript to add up all these values and get
the result (in this case, "12")

Did you get "354"?

If so, you need to convert to a number with parseFloat()

Neither parseInt nor parseFloat is *needed*; read the newsgroup FAQ.
If something like
sum += arr[i].value
concatenates strings, just include a unary + :
sum += +arr[i].value

BTW, parseInt should always be given a second parameter unless the
possible effect of not doing so is understood.

--
© John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 ©
<URL:http://www.jibbering.com/faq/> JL/RC: FAQ of news:comp.lang.javascript
<URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.

[Nicko]

Dr John Stockton wrote:

Neither parseInt nor parseFloat is *needed*; read the newsgroup FAQ.
If something like
sum += arr[i].value
concatenates strings, just include a unary + :
sum += +arr[i].value

BTW, parseInt should always be given a second parameter unless the
possible effect of not doing so is understood.

Thanks, I'll look that up - not sure I exactly know what a unary
mathematical function is or why parseInt should have a second parameter
but it's good to have something new to learn :)

Thanks again to everyone who replied!

Nicko.

[RobG]

Nicko wrote:
[...]

Thanks, I'll look that up - not sure I exactly know what a unary
mathematical function is or why parseInt should have a second parameter
but it's good to have something new to learn :)

<URL:http://www.jibbering.com/faq/#FAQ4_12>
[...]

--
Rob