<!DOCTYPE html><html lang="zh"><head> ???<meta charset="UTF-8" /> ???<meta name="viewport" content="width=device-width, initial-scale=1.0" /> ???<meta http-equiv="X-UA-Compatible" content="ie=edge" /> ???<title>Document</title> ???<script src="../0622/jquery-3.3.1.min.js" type="text/javascript" charset="utf-8"></script></head><body> ???<!--每选择一次年重置一下月和日--> ???<select class="year" onchange="month(),day()"></select> ???<!--每选择一次月重置一下日--> ???<select class="month" onchange="day()"></select> ???<select class="day"></select></body></html>
<script type="text/javascript"> ???$(function(){ ???????year(); ???????month(); ???????day(); ???}) ???function year(){ ???????var year = new Date().getFullYear(); ???????var str = ""; ???????for (var i = year-10;i<year+10;i++) { ???????????str += "<option>"+i+"</option>"; ???????} ???????$(".year").html(str); ???} ???function month(){ ???????var year = new Date().getMonth(); ???????var str = ""; ???????for (var i = 1;i<13;i++) { ???????????str += "<option>"+i+"</option>"; ???????} ???????$(".month").html(str); ???} ???function day(){// ???????选则日之前先获取年和月 ???????var year_val = $(".year").val(); ???????var month_val = $(".month").val(); ???????var day_val = 30;// ???????闰年的判断：普通年（不能被100整除的年份）能被4整除的为闰年。（如2004年就是闰年，1999年不是闰年）；世纪年（能被100整除的年份）能被400整除的是闰年。（如2000年是闰年，1900年不是闰年）； ???????if(month_val == 1 || month_val == 3 || month_val == 5 || month_val == 7 || month_val == 8 || month_val == 10 || month_val == 12){ ???????????day_val = 31; ???????}else if(month_val == 2){ ???????????if((year_val%4 == 0 && year_val%100 != 0)||year_val%400 == 0){ ???????????????day_val = 29; ???????????}else{ ???????????????day_val = 28; ???????????} ???????} ???????var year = new Date().getDate(); ???????var str = ""; ???????for (var i = 1;i<=day_val;i++) { ???????????str += "<option>"+i+"</option>"; ???????} ???????$(".day").html(str); ???}</script>0624jQuery练习：三级联动—时间
原文地址：https://www.cnblogs.com/zhangbaozhong/p/9221825.html