tryjsref_select_add2 在线代码实例

实例代码( Tip: 登录后体验更佳 )
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>W3Cschool教程(w3cschool.cn)</title>
<script>
function insertBeforeSelected(){
    var x=document.getElementById("mySelect");
    if (x.selectedIndex>=0){
        var option=document.createElement("option");
        option.text="Kiwi";
        var sel=x.options[x.selectedIndex];  
        try{
            x.add(option,sel);
        }catch(ex){
            //  对于更早的版本IE8
            x.add(option,x.selectedIndex);
        }
    }
}
</script>
</head>
<body>
<form>
<select id="mySelect">
    <option>Apple</option>
    <option>Pear</option>
    <option>Banana</option>
    <option>Orange</option>
</select>
<input type="button" onclick="insertBeforeSelected()" value="在选中项之前添加选项">
</form>
<p><b>贴士:</b>add()方法在IE8或更高版本中正常工作,要在页面中添加一个!DOCTYPE声明。对于IE 8之前的版本还要注意额外的代码。</p>
</body>
</html>
 
 
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运行结果
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