1if ($('#check_id').is(":checked"))
2{
3  // it is checked
4}

1$('#checkbox_id:checked').val();
2//if checkbox is selected than gets its value

1console.log($('input[name="locationthemes"]:checked').serialize());
2
3//or
4
5$('input[name="locationthemes"]:checked').each(function() {
6   console.log(this.value);
7});

1$("input[type='checkbox']").val();
2$('#check_id').val();

1$.each(arrayValues, function(i, val){
2
3   $("input[value='" + val + "']").prop('checked', true);
4
5});
6