NU
//using plane javascript
if(document.getElementById('on_or_off_checkbox').checked) {
//I am checked
}
//using jQuery
if($('#on_or_off_checkbox').is(':checked')){
//I am checked
}
NU
$("checkbox").is(":checked")
NU
console.log($('input[name="locationthemes"]:checked').serialize());
//or
$('input[name="locationthemes"]:checked').each(function() {
console.log(this.value);
});
NU
$('.myCheckbox').prop('checked', true);
$('.myCheckbox').prop('checked', false);
NU
var selected = [];
$('#checkboxes input:checked').each(function() {
selected.push($(this).attr('name'));
});