JavaScript:更新<;选择>;给定月份输入的天数列表
我的原始HTML有三个并排输入:JavaScript:更新<;选择>;给定月份输入的天数列表,javascript,php,Javascript,Php,我的原始HTML有三个并排输入: <select id="smonth" name="smonth" onchange="updateSDaysInput()"> <option value="Month">Month</option> <option value="1" <?php if ($smonth == '1') { echo 'selected'; } ?>>January</option>
<select id="smonth" name="smonth" onchange="updateSDaysInput()">
<option value="Month">Month</option>
<option value="1" <?php if ($smonth == '1') { echo 'selected'; } ?>>January</option>
<option value="2" <?php if ($smonth == '2') { echo 'selected'; } ?>>February</option>
<option value="3" <?php if ($smonth == '3') { echo 'selected'; } ?>>March</option>
<option value="4" <?php if ($smonth == '4') { echo 'selected'; } ?>>April</option>
<option value="5" <?php if ($smonth == '5') { echo 'selected'; } ?>>May</option>
<option value="6" <?php if ($smonth == '6') { echo 'selected'; } ?>>June</option>
<option value="7" <?php if ($smonth == '7') { echo 'selected'; } ?>>July</option>
<option value="8" <?php if ($smonth == '8') { echo 'selected'; } ?>>August</option>
<option value="9" <?php if ($smonth == '9') { echo 'selected'; } ?>>September</option>
<option value="10" <?php if ($smonth == '10') { echo 'selected'; } ?>>October</option>
<option value="11" <?php if ($smonth == '11') { echo 'selected'; } ?>>November</option>
<option value="12" <?php if ($smonth == '12') { echo 'selected'; } ?>>December</option>
</select>
<select id="sday" name="sday">
<option value="Day">Day</option>
</select>
<select id="syear" name="syear" onchange="updateSDaysInput()">
<option value="Year">Year</option>
<option value="1998" <?php if ($syear == '1998') { echo 'selected'; } ?>>1998</option>
<option value="1999" <?php if ($syear == '1999') { echo 'selected'; } ?>>1999</option>
<option value="2000" <?php if ($syear == '2000') { echo 'selected'; } ?>>2000</option>
<option value="2001" <?php if ($syear == '2001') { echo 'selected'; } ?>>2001</option>
<option value="2002" <?php if ($syear == '2002') { echo 'selected'; } ?>>2002</option>
<option value="2003" <?php if ($syear == '2003') { echo 'selected'; } ?>>2003</option>
<option value="2004" <?php if ($syear == '2004') { echo 'selected'; } ?>>2004</option>
<option value="2005" <?php if ($syear == '2005') { echo 'selected'; } ?>>2005</option>
<option value="2006" <?php if ($syear == '2006') { echo 'selected'; } ?>>2006</option>
<option value="2007" <?php if ($syear == '2007') { echo 'selected'; } ?>>2007</option>
<option value="2008" <?php if ($syear == '2008') { echo 'selected'; } ?>>2008</option>
<option value="2009" <?php if ($syear == '2009') { echo 'selected'; } ?>>2009</option>
<option value="2010" <?php if ($syear == '2010') { echo 'selected'; } ?>>2010</option>
<option value="2011" <?php if ($syear == '2011') { echo 'selected'; } ?>>2011</option>
<option value="2012" <?php if ($syear == '2012') { echo 'selected'; } ?>>2012</option>
<option value="2013" <?php if ($syear == '2013') { echo 'selected'; } ?>>2013</option>
<option value="2014" <?php if ($syear == '2014') { echo 'selected'; } ?>>2014</option>
<option value="2015" <?php if ($syear == '2015') { echo 'selected'; } ?>>2015</option>
</select>
月
>二月
>四月
>六月
>八月
>十月
>十二月
白天
年
>1999
>2001
>2003
>2005
>2007
>2009
>2011
>2013
>2015
这是相关的JavaScript代码:
syear = document.getElementById("syear");
smonth = document.getElementById("smonth");
sday = document.getElementById("sday");
function updateSDaysInput() {
"use strict";
var monthDays = findSMonthDays(smonth.value), newOption = document.createElement("option"), curLength = sday.length;
if (curLength > monthDays) {
for (i = curLength; i > monthDays; i = i - 1) {
sday.remove(i);
}
}
if (curLength < monthDays) {
for (i = curLength; i < monthDays; i = i + 1) {
newOption.text = i;
newOption.value = i.toString();
sday.add(newOption);
}
}
}
syear=document.getElementById(“syear”);
smonth=document.getElementById(“smonth”);
sday=document.getElementById(“sday”);
函数updateSDaysInput(){
“严格使用”;
var monthDays=findSMonthDays(smonth.value),newOption=document.createElement(“option”),curLength=sday.length;
如果(长度>月日){
对于(i=curLength;i>monthDays;i=i-1){
星期四。删除(i);
}
}
如果(卷曲长度<月日){
对于(i=curLength;i
如果给定
smonth
的值,则代码应酌情向sday
添加或删除选项。但它只是在sday
的底部添加了一个选项。有人知道可能是什么问题吗?将newOption=document.createElement(“option”)
移动到for循环内部,为每个循环迭代创建新元素,如下所示
if(卷长
希望对您有所帮助。您能添加findSMonthDays()函数的定义吗???这就解决了它。非常感谢。