how do I grab the value of a checkbox using javascript?

Question

I have a javascript that needs to grab the value of a checkbox when its checked and ignore its value when its not checked.

Right now i'm grabbing the value of the checkbox with:

$("input[name='tos']:checked").val()

It works when you check the box and submit the form, but if you uncheck it and resubmit the form the old value of "agree" is given. So i'm wondering how to I grab the value of a checkbox only when its checked?

mrtsherman · Accepted Answer · 2011-07-07 04:01:21Z

2

http://jsfiddle.net/dqy5H/

Here is an example fiddle. Sorry for the bad first response.

edited Jul 7, 2011 at 4:01

answered Jul 7, 2011 at 3:42

mrtsherman

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3 Comments

Incognito Over a year ago

I tried $("input[name='tos']").val() but that didn't work. Maybe I need to manually check if its checked?

Incognito Over a year ago

interesting site but I had to manually check and set values accordingly but thanks anyways.

rolling stone Over a year ago

+1 because accepted answers should always also have an upvote :)

Edgar Villegas Alvarado · Accepted Answer · 2011-07-07 03:50:46Z

2

Don't forget that unchecked checkboxes don't travel in form submission. Your code is ok, but you may have the old value stored on server side.

A workaround is tht you could have an <input type="hidden"/> that changes its value when you check/uncheck the checkbox, and read this hidden on the server. Or simply, ask if the checkbox arrived to the server, if it didn't it means it was unchecked.

Hope this helps. Cheers

answered Jul 7, 2011 at 3:50

Edgar Villegas Alvarado

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Comments

Winfield Trail · Accepted Answer · 2011-07-07 03:42:26Z

0

Two things, in order of least to most helpful :)

A checkbox should never return a value of "agree"! I'm hoping you misspoke.
~~I'm not sure the jQuery selector you used there is actually valid.~~ As the other fellow mentions, it is but it only ever sets the value when it's checked. Oof, my bad. In any case, I'd still recommend giving the checkbox an ID/unique class, and then do:

var checked = $('#toscheckbox').val();

You can add IDs without messing up the form's submission data, and I prefer them - names are so fiddly.

answered Jul 7, 2011 at 3:42

Winfield Trail

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2 Comments

Incognito Over a year ago

It still keeps the old value when I assign it an ID.

nnnnnn Over a year ago

@Kerin - Why should a checkbox never return a value of "agree"? That seems a rather arbitrary restriction. Can you please provide an explanation? (I'd most often code them to return "Y" or "true" or "1" or some other more boolean sounding value, but I wouldn't say never to other values.)

shelman · Accepted Answer · 2011-07-07 03:59:16Z

0

Try giving it an id and calling .is(':checked') like in this article to see if it is checked or not.

http://jquery-howto.blogspot.com/2008/12/how-to-check-if-checkbox-is-checked.html

answered Jul 7, 2011 at 3:59

shelman

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