JavaScript操作Select与Option的完整指南：动态创建、增删改及跨浏览器兼容

动态创建Select下拉框

1.动态创建select

function createSelect(){
var mySelect = document.createElement_x("select");
 mySelect.id = "mySelect"; 
 document.body.appendChild(mySelect);
 }

function addOption(){
//根据id查找对象，
 var obj=document.getElementByIdx_x('mySelect');
//添加一个选项
obj.add(new Option("文本","值")); //这个只能在IE中有效
 obj.options.add(new Option("text","value")); //这个兼容IE与firefox
 }

function removeAll(){
var obj=document.getElementByIdx_x('mySelect');
obj.options.length=0;
     }

function removeOne(){
var obj=document.getElementByIdx_x('mySelect');
//index,要删除选项的序号，这里取当前选中选项的序号
var index=obj.selectedIndex;
obj.options.remove(index);
 }

获取Option的值与文本

var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].value;

6.获得选项option的文本

var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].text;

修改Option选项

7.修改选项option

var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index]=new Option("新文本","新值");

删除整个Select元素

8.删除select

function removeSelect(){
var mySelect = document.getElementByIdx_x("mySelect");
mySelect.parentNode.removeChild(mySelect);
     }

完整实例代码：联动Select与DOM操作

整个实例的完整代码如下：

<!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 $(id)
    {
return document.getElementByIdx_x(id)
    }
function show()
    {
var selectObj=$("area")
var myOption=document.createElement_x("option")
myOption.setAttribute("value","10")
myOption.appendChild(document.createTextNode("上海"))
var myOption1=document.createElement_x("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_x("select")
sh.add(new Option("浦东新区","101"))
sh.add(new Option("黄浦区","102"))
sh.add(new Option("徐汇区","103"))
sh.add(new Option("普陀区","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_x("select")
nj.add(new Option("玄武区","201"))
nj.add(new Option("白下区","202"))
nj.add(new Option("下关区","203"))
nj.add(new Option("栖霞区","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" onchange="choice()">
</select>
</div>
<input type=button value="显示" onclick="show()">
<input type=button value="计算结点" onclick="calc()">
<input type=button value="删除" onclick="remove()">
</body>
</html>

改进版：跨浏览器兼容的Option增删改

改进版：在select中添加、修改、删除option元素

function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var word = document.createElement_x("OPTION");
word.text = arguments[i];
watch.keywords.add(word); // watch. is form name
}
}
function watch_add(f){ // 增加
var word = document.createElement_x("OPTION");
word.text = f.word.value;
f.keywords.add(word);
}

但上述 add() 方法只在IE下有效，为兼容FF和Opera，对上述代码进行了一下改进，改动后代码如下：

function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var oOption=new Option(arguments[i],arguments[i]);
document.getElementByIdx_x("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;
}

改进版完整实例：表单交互与保存

整个实例的完整代码如下：

<!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.getElementByIdx_x("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){ // 编辑
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){ // 删除
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" onchange="watch_sel(this.form)"></select><br>
<script language="javascript">
<!--
watch_ini("我","你","妳","他","她","它","尔"); // 初始关键词
//-->
</script>
<input type="text" name="word" /><br />
<input type="button" value="增加" onclick="watch_add(this.form);" />
<input type="button" value="修改" onclick="watch_mod(this.form);" />
<input type="button" value="删除" onclick="watch_del(this.form);" />
<input type="button" value="保存" onclick="watch_set(this.form);" />
</form>

字符串转数组技巧

用一个字符串创建一个数组方法:

<script language="javascript">
</body>
</html>
<script>
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>

IE与Firefox兼容性说明

今天调试了一段js，在ie上运行良好，在火狐上调试出现错误，查资料发现

obj.add(new Option("文本","值")); //这个只能在IE中有效 obj.options.add(new Option("text","value")); //这个兼容IE与firefox

因为这段代码，在网上查资料收藏了这篇文章，实时的温故js