$("#target")[0].selectedIndex = 0;

它只适用于我在最后使用触发器('change')，就像这样:

$("#target option:first").attr('selected','selected').trigger('change');

// remove "selected" from any options that might already be selected
$('#target option[selected="selected"]').each(
    function() {
        $(this).removeAttr('selected');
    }
);


// mark the first option as selected
$("#target option:first").attr('selected','selected');

var firstItem = $(“感兴趣类型”)。(“selectedIndex”道具,0)。瓦尔();

控制台日志(firstItem)。

$("#target")[0].selectedIndex = 0;

Use:

alert($( "#target option:first" ).text());