how to send js array from ajax

$.ajax({
            type: "POST",
            url: "submit",
            data:JSON.stringify(detailsArr),
            success: function(html){
              alert( "Submitted");
                }
          });
$.ajax({
            type: "POST",
            url: "submit",
            data: ({detailsArr : detailsArr }),
            success: function(html){
              alert( "Submitted");
                }
          });