get value of selected checkbox jquery

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

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

//or

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

var selected = [];
$('#checkboxes input:checked').each(function() {
    selected.push($(this).attr('name'));
});

var values = $('input[name=grepperRocks]:checked')
               .map(() => { return this.value }).get();