如何使用 jQuery 將無序列表轉換為選擇下拉清單？

<ul class="selectdropdown">
    <li><a href="one.html" target="_blank">one</a></li>
    <li><a href="two.html" target="_blank">two</a></li>
    <li><a href="three.html" target="_blank">three</a></li>
    <li><a href="four.html" target="_blank">four</a></li>
    <li><a href="five.html" target="_blank">five</a></li>
    <li><a href="six.html" target="_blank">six</a></li>
    <li><a href="seven.html" target="_blank">seven</a></li>
</ul>

<select>
    <option value="one.html" target="_blank">one</option>
    <option value="two.html" target="_blank">two</option>
    <option value="three.html" target="_blank">three</option>
    <option value="four.html" target="_blank">four</option>
    <option value="five.html" target="_blank">five</option>
    <option value="six.html" target="_blank">six</option>
    <option value="seven.html" target="_blank">seven</option>
</select>

$(function() {
    $('ul.selectdropdown').each(function() {
        var $select = $('<select>');

        $(this).find('a').each(function() {
            var $option = $('<option>');
            $option.attr('value', $(this).attr('href')).html($(this).html());
            $select.append($option);
        });

        $(this).replaceWith($select);
    });
});