1.動態創建select
function createSelect(){
var mySelect = document.createElement("select");
mySelect.id = "mySelect";
document.body.appendChild(mySelect);
}
2.添加選項option
function addOption(){
//根據id查找對象，
var obj=document.getElementById('mySelect');
//添加一個選項
obj.add(new Option("文本","值")); //這個只能在IE中有效
obj.options.add(new Option("text","value")); //這個兼容IE與firefox
}
3.刪除所有選項option
function removeAll(){
var obj=document.getElementById('mySelect');
obj.options.length=0;
}
4.刪除一個選項option
function removeOne(){
var obj=document.getElementById('mySelect');
//index,要刪除選項的序號，這裏取當前選中選項的序號
var index=obj.selectedIndex;
obj.options.remove(index);
}
5.獲得選項option的值
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序號，取當前選中選項的序號
var val = obj.options[index].value;
6.獲得選項option的文本
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序號，取當前選中選項的序號
var val = obj.options[index].text;
7.修改選項option
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序號，取當前選中選項的序號
var val = obj.options[index]=new Option("新文本","新值");
8.刪除select
function removeSelect(){
var mySelect = document.getElementById("mySelect");
mySelect.parentNode.removeChild(mySelect);
}
整個實例的完整代碼如下：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//ZH-CN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html">
<head>
<script language=JavaScript>
function $(id)
{
return document.getElementById(id)
}
function show()
{
var selectObj=$("area")
var myOption=document.createElement("option")
myOption.setAttribute("value","10")
myOption.appendChild(document.createTextNode("上海"))
var myOption1=document.createElement("option")
myOption1.setAttribute("value","100")
myOption1.appendChild(document.createTextNode("南京"))
selectObj.appendChild(myOption)
selectObj.appendChild(myOption1)
}
function choice()
{
var index=$("area").selectedIndex;
var val=$("area").options[index].getAttribute("value")
if(val==10)
{
var i=$("context").childNodes.length-1;
var remobj=$("context").childNodes[i];
remobj.removeNode(true)
var sh=document.createElement("select")
sh.add(new Option("浦東新區","101"))
sh.add(new Option("黃浦區","102"))
sh.add(new Option("徐彙區","103"))
sh.add(new Option("普陀區","104"))
$("context").appendChild(sh)
}
if(val==100)
{
var i=$("context").childNodes.length-1;
var remobj=$("context").childNodes[i];
remobj.removeNode(true)
var nj=document.createElement("select")
nj.add(new Option("玄武區","201"))
nj.add(new Option("白下區","202"))
nj.add(new Option("下關區","203"))
nj.add(new Option("棲霞區","204"))
$("context").appendChild(nj)
}
}
function calc()
{
var x=$("context").childNodes.length-1;
alert(x)
}
function remove()
{
var i=$("context").childNodes.length-1;
var remobj=$("context").childNodes[i];
remobj.removeNode(true)
}
</script>
<body>
<div id="context">
<select id="area" οnchange="choice()">
</select>
</div>
<input type=button value="顯示" οnclick="show()">
<input type=button value="計算結點" οnclick="calc()">
<input type=button value="刪除" οnclick="remove()">
</body>
</html>
改進版：在select中添加、修改、刪除option元素
function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var word = document.createElement("OPTION");
word.text = arguments[i];
watch.keywords.add(word); // watch. is form name
}
}
function watch_add(f){ // 增加
var word = document.createElement("OPTION");
word.text = f.word.value;
f.keywords.add(word);
}
但上述 add() 方法只在IE下有效，爲兼容FF和Opera，對上述代碼進行了一下改進，改動後代碼如下： function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var oOption=new Option(arguments[i],arguments[i]);
document.getElementById("MySelect")[i]=oOption;
}
}
function watch_add(f){ // 增加
var oOption=new Option(f.word.value,f.word.value);
f.keywords[f.keywords.length]=oOption;
}
整個實例的完整代碼如下：
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<title>javascript select options text value</title>
<meta name="keywords" content="javascript select options text value add modify delete set">
<meta name="description" content="javascript select options text value add modify delete set">
<script language="javascript">
<!--
function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var oOption=new Option(arguments[i],arguments[i]);
document.getElementById("MySelect")[i]=oOption;
}
}
function watch_add(f){ // 增加
var oOption=new Option(f.word.value,f.word.value);
f.keywords[f.keywords.length]=oOption;
}
function watch_sel(f){ // 編輯
f.word.value = f.keywords[f.keywords.selectedIndex].text;
}
function watch_mod(f){ // 修改
f.keywords[f.keywords.selectedIndex].text = f.word.value;
}
function watch_del(f){ // 刪除
f.keywords.remove(f.keywords.selectedIndex);
}
function watch_set(f){ // 保存
var set = "";
for(var i=0; i<f.keywords.length; i++){
set += f.keywords[i].text + ";";
}
confirm(set);
}
//-->
</script>
</head>
<body>
<form name="watch" method="post" action="">
<select id="MySelect" name="keywords" size="10" οnchange="watch_sel(this.form)"></select><br>
<script language="javascript">
<!--
watch_ini("我","你","妳","他","她","它","爾"); // 初始關鍵詞
//-->
</script>
<input type="text" name="word" /><br />
<input type="button" value="增加" οnclick="watch_add(this.form);" />
<input type="button" value="修改" οnclick="watch_mod(this.form);" />
<input type="button" value="刪除" οnclick="watch_del(this.form);" />
<input type="button" value="保存" οnclick="watch_set(this.form);" />
</form>
用一個字符串創建一個數組方法:
<script language="javascript">
function spli(){
datastr="2,2,3,5,6,6";
var str= new Array();
str=datastr.split(",");
for (i=0;i<str.length ;i++ )
{ document.write(str[i]+"<br/>"); }
}
spli();
</script>