Form
对于select的操作：
1. 属性
设select的id为selectid
用selectid.options[i].text来访问/修改各个选项的文字；
用selectid.options[i].value来访问/修改各个选项对应的值。
用selectid.options[i].text来访问/修改各个选项的文字；
用selectid.options[i].value来访问/修改各个选项对应的值。
2. 插入值
<select id=slt1>
<option>option1
<option>option2
</select>
<button onclick=ChangeOptionText()>change</button>
<script language=javascript>
function ChangeOptionText()
{
selectid.options[0].innerText=prompt('input first option caption:',slt1.options[0].text);
}
</script>
<option>option1
<option>option2
</select>
<button onclick=ChangeOptionText()>change</button>
<script language=javascript>
function ChangeOptionText()
{
selectid.options[0].innerText=prompt('input first option caption:',slt1.options[0].text);
}
</script>
3. 设置选择
for (var i = 0; i < selectid.options.length; i++) {
if (selectid.options[i].text == objItemText) {
selectid.options[i].selected = true;
break;
}
}
if (selectid.options[i].text == objItemText) {
selectid.options[i].selected = true;
break;
}
}
4. 删除所有的
selectidt.options.length = 0;
5.
删除select中选中的项
function jsRemoveSelectedItemFromSelect(objSelect) {
var length = objSelect.options.length - 1;
for(var i = length; i >= 0; i--){
if(objSelect[i].selected == true){
objSelect.options[i] = null;
}
}
}
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<form action= "dreamdu.php" method= "post" id= "dreamduform">
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<fieldset>
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<legend>你对梦之都的感觉:</legend>
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<label for= "select">你对梦之都的感觉</label>
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<select size= "1" id= "select" name= "select">
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<option>很全面,很好</option>
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<option selected= "selected">一般般吧,还要努力</option>
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<option>有很多问题,不过还可以</option>
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</select>
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</fieldset>
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<fieldset>
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<legend>你在梦之都想学习的编程语言:</legend>
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<label for= "multipleselect">你在梦之都想学习的编程语言</label>
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<select size= "10" multiple= "multiple" id= "multipleselect" name= "multipleselect">
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<option selected= "selected">XHTML</option>
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<option>CSS</option>
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<option>JAVASCRIPT</option>
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<option>XML</option>
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<option selected= "selected">PHP</option>
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<option>C#</option>
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<option>JAVA</option>
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<option>C++</option>
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<option>PERL</option>
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</select>
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</fieldset>
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</form>
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<form action= "dreamdu.php" method= "post" id= "dreamduform">
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<fieldset>
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<legend>用户名与密码:</legend>
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<input id= "hiddenField" name= "hiddenField" type= "hidden" value= "hiddenvalue" />
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<label for= "username">用户名:</label>
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<input type= "text" id= "username" name= "username" value= "dreamdu" />
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<label for= "pass">密码:</label>
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<input type= "password" id= "pass" name= "pass" />
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</fieldset>
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<fieldset>
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<legend>性别:</legend>
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<label for= "boy">男</label>
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<input type= "radio" value= "1" id= "sex" name= "sex" />
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<label for= "girl">女</label>
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<input type= "radio" value= "2" id= "sex" name= "sex" />
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<label for= "sex">保密</label>
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<input type= "radio" value= "3" id= "sex" name= "sex" />
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</fieldset>
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<fieldset>
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<legend>我最喜爱的:</legend>
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<label for= "computer">计算机</label>
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<input type= "checkbox" value= "1" id= "fav" name= "fav" />
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<label for= "trval">旅游</label>
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<input type= "checkbox" value= "2" id= "fav" name= "fav" />
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<label for= "buy">购物</label>
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<input type= "checkbox" value= "3" id= "fav" name= "fav" />
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</fieldset>
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<fieldset>
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<legend>对梦之都的意见:</legend>
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<label for= "select">你对梦之都的感觉</label>
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<select size= "1" id= "select" name= "select">
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<option>很全面,很好</option>
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<option>一般般吧,还要努力</option>
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<option>有很多问题,不过还可以</option>
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</select>
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</fieldset>
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<fieldset>
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<legend>梦之都编程语言选择:</legend>
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<label for= "multipleselect">你想在梦之都学习的编程语言</label>
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<select size= "10" multiple= "multiple" id= "multipleselect" name= "multipleselect">
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<option>XHTML</option>
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<option>CSS</option>
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<option>JAVASCRIPT</option>
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<option>XML</option>
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<option>PHP</option>
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<option>C#</option>
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<option>JAVA</option>
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<option>C++</option>
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<option>PERL</option>
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</select>
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</fieldset>
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<fieldset>
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<legend>我要在梦之都学:</legend>
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<label for= "WebDesign">选择一个你在梦之都最想学的</label>
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<select id= "WebDesign" name= "WebDesign">
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<optgroup label= "client">
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<option value= "HTML">HTML</option>
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<option value= "CSS">CSS</option>
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<option value= "javascript">javascript</option>
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</optgroup>
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<optgroup label= "server">
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<option value= "PHP">PHP</option>
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<option value= "ASP">ASP</option>
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<option value= "JSP">JSP</option>
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</optgroup>
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<optgroup label= "database">
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<option value= "Access">Access</option>
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<option value= "MySQL">MySQL</option>
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<option value= "SQLServer">SQLServer</option>
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</optgroup>
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</select>
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</fieldset>
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<fieldset>
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<legend>个人化信息:</legend>
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<label for= "myimage">个性照片上传</label>
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<input type= "file" id= "myimage" name= "myimage" size= "35" maxlength= "255" />
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<label for= "contactus">联系我们</label>
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<textarea cols= "50" rows= "10" id= "contactus" name= "contactus">
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可爱的猴子
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</textarea>
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</fieldset>
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<fieldset>
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<legend>提交:</legend>
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<input type= "submit" value= "submit" id= "submit" name= "submit" />
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<input type= "reset" value= "reset" id= "reset" name= "reset" />
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</fieldset>
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</form>
var length = objSelect.options.length - 1;
for(var i = length; i >= 0; i--){
if(objSelect[i].selected == true){
objSelect.options[i] = null;
}
}
}
6.删除
for (var i = 0; i < objSelect.options.length; i++) {
if (objSelect.options[i].value == objItemValue) {
objSelect.options.remove(i);
break;
}
}
if (objSelect.options[i].value == objItemValue) {
objSelect.options.remove(i);
break;
}
}
7.增加
var varItem = new Option(objItemText, objItemValue);
objSelect.options.add(varItem);
objSelect.options.add(varItem);