Why jQuery throwing undefined for checkbox checked property ?

Question

Following code works inside the onchange property of checkbox:

 onchange="if(this.checked)$('#row_date').show();else $('#row_date').hide();"

but jquery

alert($('#apply_range').checked) // throw undefined, either checked or unchecked

not working.

Possible duplicate of [Check if checkbox is checked with jQuery](http://stackoverflow.com/questions/2204250/check-if-checkbox-is-checked-with-jquery) — Michał Perłakowski, Jul 13 '16 at 09:42
I recommend you don't use inline JS event attributes. Instead use an event listener or jQuery's on method. — evolutionxbox, Jul 13 '16 at 09:46

score 3 · Accepted Answer · answered Jul 13 '16 at 09:40

3

checked is a property of the DOMElement, not a jQuery object. To get that property from the jQuery object, use prop():

console.log($('#apply_range').prop('checked'));

Or you can access the DOMElement in the jQuery object directly like this:

console.log($('#apply_range')[0].checked);

// or

console.log($('#apply_range').get(0).checked);

answered Jul 13 '16 at 09:40

Rory McCrossan

Isn't this possible for jQuery to fallback to DOMElement property if property is requested, just curious – justnajm Jul 13 '16 at 16:03
Possible, yes. But it would be a massive breaking change, and possibly lead to a lot of confusion. By specifically having to use `prop('propName')` or `get(0).propName` your intent of getting the property value is explicit. – Rory McCrossan Jul 13 '16 at 16:05

score 0 · Answer 2 · answered Jul 13 '16 at 09:40

0

You have to either use $('#apply_range').is(":checked") or directly access DOM element: $('#apply_range')[0].checked.

answered Jul 13 '16 at 09:40

2 Answers2