javascript选择的值

Siv*_*va 3 html javascript

            <div id="selected_options">
            <select onchange="test()" id="selected_options">
            <option value="0" selected>-Select-</option>
            <option value="1">Communication</option>
            <option value="2">Hardware</option>
            </select>
    </div>
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我已经为选定的值编写了一个函数,但是当我对所选值进行警报时,它显示为undefined,函数是

      function test() {
                    var get_id = document.getElementById('selected_options');
                    var result = get_id.options[get_id.selectedIndex].value;
                    alert(result);
                      }
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任何人请告诉我这是什么错误?

KJY*_*葉家仁 6

你也有两个id selected_options.因为这个JSFiddle发出警告:

<div id="selected_options">
    <select onchange="test()" id="selected_opt">
        <option value="0" selected>-Select-</option>
        <option value="1">Communication</option>
        <option value="2">Hardware</option>
    </select>
</div>

function test() {
    var get_id = document.getElementById('selected_opt');
    console.log(get_id);
    var result = get_id.options[get_id.selectedIndex].value;
    alert(result);
}
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