菜鸟求js代码

初学JS，请教高手有数组var a = [1,2,3]; 根据数组内容弹出选择框 1，2，3，
单击选中其中一个就把选中的值赋给一个变量i.如选2 i=2~~求代码

解决方案 »

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<script>
var ary =[1,2,3];
var ddl = document.createElement("SELECT");
for(var i = 0 ; i <ary.length;i++)
{
    var op = document.createElement("option");
    op.value = ary[i] ;
    op.innerHTML = ary[i];
    ddl.appendChild(op);
}   document.getElementById("div1").appendChild(ddl);ddl.onchange = function()
{
var j = ddl.value;
    alert(j);

}
</script><div id="div1" >

   </div>
不好意思，我的HTML文件是这样，怎么测试不了呢？？~~<html>
<head></head>
<body>
<script>
var ary =[1,2,3];
var ddl = document.createElement("SELECT");
for(var i = 0 ; i <ary.length;i++)
{
    var op = document.createElement("option");
    op.value = ary[i] ;
    op.innerHTML = ary[i];
    ddl.appendChild(op);
}   document.getElementById("div1").appendChild(ddl);ddl.onchange = function()
{
var j = ddl.value;
    alert(j);

}
</script><div id="div1" >

   </div>
</body>
</html>
看来1楼得把HTML Code放前面才行
<html>
<head></head>
<body>
<div id="div1" >

   </div>
<script>
var ary =[1,2,3];
var ddl = document.createElement("SELECT");
for(var i = 0 ; i <ary.length;i++)
{
    var op = document.createElement("option");
    op.value = ary[i] ;
    op.innerHTML = ary[i];
    ddl.appendChild(op);
}   document.getElementById("div1").appendChild(ddl);ddl.onchange = function()
{
var j = ddl.value;
    alert(j);

}
</script>
</body>
</html>
<html>
<head>
<script>
function aa(){
var ary =[1,2,3];
var ddl = document.createElement("SELECT");
for(var i = 0 ; i <ary.length;i++)
{
    var op = document.createElement("option");
    op.value = ary[i] ;
    op.innerHTML = ary[i];
    ddl.appendChild(op);
}   document.getElementById("div1").appendChild(ddl);ddl.onchange = function()
{
var j = ddl.value;
    alert(j);

}
}
</script></head>
<body>
<input type="button" onclick="aa()" value="测试">
<div id="div1" >

   </div>
</body>
</html>