如何确定从选择字段中选择哪个选项

Does anyone know how to retrieve the option chosen from a drop-down select box?

有谁知道如何检索从下拉选择框中选择的选项?

I'm using document.getElementById("mySelect").value and it doesn't seem to be working...

我正在使用document.getElementById(“mySelect”)。value并且它似乎不起作用......

3 个解决方案

#1

document.getElementById("mySelect").options[document.getElementById("mySelect").selectedIndex].value

#2

Are you sure your drop-down has a value in it? Did you provide values for it?

你确定你的下拉有价值吗?你为它提供了价值吗?

<select id="dropdownBox">
<option value="val1">value 1</option>
<option value="val2">value 2</option>
<option value="val3">value 3</option>
<option value="val4">value 4</option>
</select>

The values are val1, val2...

值为val1,val2 ......

#3

It's better for code optimization to do something like:

代码优化最好做以下事情:

var o = document.getElementById("mySelect");
o.options[o.selectedIndex].value;

jQuery alternative:

$("#mySelect").val();