javascript - Get the value of checked checkbox?

Question

So I've got code that looks like this:

<input class="messageCheckbox" type="checkbox" value="3" name="mailId[]">
<input class="messageCheckbox" type="checkbox" value="1" name="mailId[]">

I just need Javascript to get the value of whatever checkbox is currently checked.

EDIT: To add, there will only be ONE checked box.

Answer 1

None of the above worked for me but simply use this:

document.querySelector('.messageCheckbox').checked;

Happy coding.