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<html>
<head>
<title>
select test
</title>
<script>
function removeF(){
var wednes=document.form1.select.options;
var index;
alert("wednes[2]="+wednes[2].text);
var already=true;
for(index=0;index<wednes.length;index++){
if(wednes[index].text=="Wednesday"){
wednes[index]=null;
already=false;
}
}
if(already){
alert("There is no wednesday here!");
}
}
function addF(){
var wednes=document.form1.select.options;
var haveWednes=false;
var index;
for(index=0;index<wednes.length;index++){
if(wednes[index].text=="Wednesday"){
haveWednes=true;
}
}
if(!haveWednes){
wednes[wednes.length]=new Option();
//alert(wednes[]);
for(index=wednes.length-1;index>2;index--){
we=wednes[index-1];
wednes[index]=we;/////////////////为什么这里赋值不成功？
//但如果改成new Option("wrgvw",index);却能赋值？？？？
//alert(wednes[index]);
alert("we="+we+" index="+index+" wednes[index]="+wednes[index]);
}
//wednes[2]=new Option("Wednesday",2);
}
else{
alert("do you want to have Two Wednesday?")
}
}
</script>
</head>
<body>
<form name="form1">
<select name="select" size=3>
<option value=0>Monday</option>
<option value=1>Tuesday</option>
<option value=2>Wednesday</option>
<option value=3>Thursday</option>
<option value=4>Friday</option>
<option value=5>Saturday</option>
<option value=6>Sunday</option>
</select>
<br>
<input type="button" value="Remove Wednesday" name="remove" onclick="removeF()"/>
<br>
<br>
<input type="button" value="add Wednesday" name="add" onclick="addF()"/>
</form>
</body>
</html>
<head>
<title>
select test
</title>
<script>
function removeF(){
var wednes=document.form1.select.options;
var index;
alert("wednes[2]="+wednes[2].text);
var already=true;
for(index=0;index<wednes.length;index++){
if(wednes[index].text=="Wednesday"){
wednes[index]=null;
already=false;
}
}
if(already){
alert("There is no wednesday here!");
}
}
function addF(){
var wednes=document.form1.select.options;
var haveWednes=false;
var index;
for(index=0;index<wednes.length;index++){
if(wednes[index].text=="Wednesday"){
haveWednes=true;
}
}
if(!haveWednes){
wednes[wednes.length]=new Option();
//alert(wednes[]);
for(index=wednes.length-1;index>2;index--){
we=wednes[index-1];
wednes[index]=we;/////////////////为什么这里赋值不成功？
//但如果改成new Option("wrgvw",index);却能赋值？？？？
//alert(wednes[index]);
alert("we="+we+" index="+index+" wednes[index]="+wednes[index]);
}
//wednes[2]=new Option("Wednesday",2);
}
else{
alert("do you want to have Two Wednesday?")
}
}
</script>
</head>
<body>
<form name="form1">
<select name="select" size=3>
<option value=0>Monday</option>
<option value=1>Tuesday</option>
<option value=2>Wednesday</option>
<option value=3>Thursday</option>
<option value=4>Friday</option>
<option value=5>Saturday</option>
<option value=6>Sunday</option>
</select>
<br>
<input type="button" value="Remove Wednesday" name="remove" onclick="removeF()"/>
<br>
<br>
<input type="button" value="add Wednesday" name="add" onclick="addF()"/>
</form>
</body>
</html>
...全文
请发表友善的回复…
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tiffany343751280 2012-10-15
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晕死了
泡泡鱼_ 2012-10-14
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手误：文件=文本
泡泡鱼_ 2012-10-14
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//你既然已经定义了：
var wednes=document.form1.select.options;
//想添加一个列表项,使用下面的方法就行了
wednes.add(new Option("文件","值"));其他的没必要纠结，感觉有点浪费时间的说
tingyingg 2012-10-14
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错了，是wednes[index]=wednes[index]也能赋值
tingyingg 2012-10-14
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改成wednes[index]=wednesday[index]也能赋值，为什么就index-1不能能？高手帮忙啊！
tingyingg 2012-10-14
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这不是赋值吗？
Go 旅城通票 2012-10-14
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wednes[index]=we;/////////////////为什么这里赋值不成功？
你这里是给option添加wednes.length-1~2之间的数字自定义属性
和new Option不一样，
你这里是给option添加wednes.length-1~2之间的数字自定义属性
和new Option不一样，
