How to retrieve and display a data in Codeigniter with Jquery's Ajax

$('form.ajaxForm').on('submit',function() {
                $.ajax({
                        type: 'POST',
                        url: 'YOUR LOCAL HOST HERE OR BASE URL/maincontroller/testForAjax',
                        data:{ search: $("#searchInput").val(), searchType: $("#searchTypeID").val() },
                        dataType: 'JSON',
                        success: function(smg) {
                                
                        }
                });
        });