js处理年月日下拉菜单变化

来源：互联网发布：php pdo sqlserver 编辑：程序博客网时间：2024/05/21 10:11

function onload(){var now = new Date();var year = now.getYear();//获得年份，不过是1900年到现在的数值year = year + 1900 - 18;//因为要4位数字年份又要求使用者大于18岁var yearList = document.getElementById("yearList");for(var i = 0;i < (year-(year - 80));i++){//为年份下拉菜单倒序输出年份var addYear = year - i;yearList.options[i] = new Option(addYear,addYear);}yearChange();}/** *年份改变，没啥好说的，月日下拉菜单清空重排就行了 */function yearChange(){var monthList = document.getElementById("monthList");monthList.innerHTML = "";for(var i = 0;i < 12;i++){monthList.options[i] = new Option(i+1,i+1); }var dayList = document.getElementById("dayList");dayList.innerHTML = "";for(var i = 0;i < 31;i++){dayList.options[i] = new Option(i+1,i+1);}}/** *月份改变 */function monthChange(m){//m为改变的月份值var year = parseInt(document.getElementById("yearList").value);//转为整形var day = 31;switch(parseInt(m))//做一下月份的判断，为日期复制{case 1,3,5,7,8,10,12:day = 31;break;case 2:day = 28;break;case 4,6,9,11:day = 30;break;}if(day == 28)//二月份的情况下{if ((year%4==0 && year%100!=0) || (year%400==0))//闰年公式，判断是否为闰年{day = 29;}}var dayList = document.getElementById("dayList");dayList.innerHTML = "";for(var i = 0;i < day;i++){dayList.options[i] = new Option(i+1,i+1);}}

html代码

<select id="yearList" class="yearSelect" onchange="yearChange()"></select><select id="monthList" class="nonYearSelect" onchange="monthChange(this.value)"></select><select id="dayList" class="nonYearSelect"></select>