Answers for "jquery checkbox checked selector"

jQuery is checkbox checked

//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
}

checkbox is checked jquery

$(your_checkbox).is(':checked');

is checked checkbox jquery

$('#' + id).is(":checked")