Stop Internet Explorer from casting my index to an int

Question

I'm indexing through a form with something like:

var i = 0;
var s = new String( i+'.prop');
var v = document.formName[s].value;

but what I get is actually:

document.formName[0].value

it appears that my index value "0.prop" is getting cast to an int, only in Internet Explorer (8)

any ideas on how to stop that?

UPDATE: here's a jsfiddle that exhibits the problem. Should return '111', but it returns foo in IE8.

jlaceda · Answer 1 · 2012-04-19T17:38:05.593

1

Use the toString() method:

var i = 0;
var s = i.toString() + '.prop';

typeof(s) === string // true

edited Apr 19 '12 at 17:38

answered Apr 19 '12 at 17:23

jlaceda

score 1 · Accepted Answer · edited May 23 '17 at 10:24

1

FOUND IT! according to this answer NAME attributes must start with a letter not a number...

so adapting your html and using

var i = 0;
var s = 'prop_'+i;
var v = document.formName[s].value;

will work (I also updated the fiddle)

edited May 23 '17 at 10:24

Community

answered Apr 19 '12 at 17:26

Tobias Krogh

http://jsfiddle.net/KPEv3/ works for me... or did I missed something regarding your question? – Tobias Krogh Apr 19 '12 at 17:38
curious, that works for me. I sliced what I thought was the problem code out of a bigger chunk. Let me go further up the chain. Thanks for your answer and follow up. – Jason Crowther Apr 19 '12 at 17:55
you could flag / vote this answer as an answer for this particular question, if you want to :) – Tobias Krogh Apr 19 '12 at 18:03
updated question to include a fiddle that exhibits the problem. +tobias, just needed some more elements in the form to exhibit the problem. – Jason Crowther Apr 19 '12 at 18:13

score 0 · Answer 3 · edited Jul 16 '12 at 18:50

0

Do

var s = new String(''+i+'.prop');

Or

var s = new String( i.toString()+'.prop');

edited Jul 16 '12 at 18:50

Wouter Dorgelo

answered Apr 19 '12 at 17:22

CrayonViolent

the String constructor is not needed here – Bergi Apr 19 '12 at 17:30
I didn't add that in there, I just copied the OP's code..so how about removing that negative vote? – CrayonViolent Apr 19 '12 at 17:37

3 Answers3