jQuery 按值 Select 选项元素

我有一个由SPAN元素包装的SELECT元素.不允许我使用SELECT ID，但允许我使用SPAN ID. 我正在try 编写一个javascript/jQuery函数，其中的输入是数字i，它是SELECT选项的值之一.该功能会将相关选项变为Selected(已 Select ).

<span id="span_id">
    <select id="h273yrjdfhgsfyiruwyiywer" multiple="multiple">
        <option value="1">cleaning</option>
        <option value="2">food-2</option>
        <option value="3">toilet</option>
        <option value="4">baby</option>
        <option value="6">knick-knacks</option>
        <option value="9">junk-2</option>
        <option value="10">cosmetics</option>
    </select>
</span>

I wrote something as follows (this does not completely work, which is why I am posting this question):

function select_option(i) {

    options = $('#span_id').children('select').children('option');
    //alert(options.length); //7
    //alert(options[0]); //[object HTMLOptionElement]
    //alert(options[0].val()); //not a jquery element
    //alert(options[0].value); //1

    //the following does not seem to work since the elements of options are DOM ones not jquery's
    option = options.find("[value='" + i + "']");
    //alert(option.attr("value")); //undefined
    option.attr('selected', 'selected');

}

Thanks!