var isFirst = true; ???$(function () { ???????//一级 ???????$("#City").change(function () { ???????????var url = "/TWAddress/GetTownship/?selected=" + $("#City").val() + ""; ???????????$.getJSON(url, function (data) { ???????????????if (isFirst == true) { ???????????????????$("#City option:first").remove(); ???????????????????isFirst = false; ???????????????}设置一个全局变量
方法执行一次js
原文地址：https://www.cnblogs.com/Neil-Peng/p/9045585.html