JQuery:
var selected = "";
$("#selectId :selected").each(function(){ selected += $(this).val() + ","; });
var e = document.getElementById("selectId");
alert(getSelectValues(e));function getSelectValues(select) { var result = ""; var options = select && select.options; var opt; for (var i=0, iLen=options.length; i<iLen; i++) { opt = options[i]; if (opt.selected) { result += (opt.value || opt.text) + ","; } } return result;}原文：https://www.cnblogs.com/wylngg/p/12091285.html