Answers for "jquery get checkbox not checked value"

jquery check if checkbox is not checked

if (!$("#checkboxID").is(":checked")) {
    // do something if the checkbox is NOT checked
}

jquery get value checkbox checked

console.log($('input[name="locationthemes"]:checked').serialize());

//or

$('input[name="locationthemes"]:checked').each(function() {
   console.log(this.value);
});