find all unchecked checkbox in jquery

Question

I have a list of checkboxes:

<input type="checkbox" name="answer" id="id_1' value="1" />
<input type="checkbox" name="answer" id="id_2' value="2" />
...
<input type="checkbox" name="answer" id="id_n' value="n" />

I can collect all the values of checked checkboxes; my question is how can get all the values of unchecked checkboxes? I tried:

$("input:unchecked").val();

to get an unchecked checkbox's value, but I got:

Syntax error, unrecognized expression: unchecked.

can anybody shed a light on this issue? thank you!

Answer 1

As the error message states, jQuery does not include a :unchecked selector.
Instead, you need to invert the :checked selector:

$("input:checkbox:not(:checked)")