使用jquery中数据表的正则表达式查找所有元素

Question

I have a data table that has a structure like:

<tbody>
<tr>
    <td>ABC<td>
    <td id="invNumbers0">DEF<td>
</tr>
<tbody>
<tr>
    <td>GHI<td>
    <td id="invNumbers1">JKL<td>
</tr>
<tr>
    <td>MNO<td>
    <td id="invNumbers2">PQR<td>
</tr>
<tbody>
<tr>
    <td>STU<td>
    <td id="invNumbers3">WXY<td>
</tr>

I want to find the count of whose id starts with "invNumbers"

I have tried using below code and it is giving empty results

var table = $('#result').DataTable();
        $('#result').on( 'page.dt', function () {
            var uniInv = 0;
            alert( 'Table redrawn' );

            if(!isEmpty($('#result').find('$([id^="invnumbers"]').val())){
                uniInv++;
            }
            alert(uniInv);
        });

Answer 1

How about using $().length ? exmaple:

alert($('[id^=invNumbers]').length);

fiddle:

https://jsfiddle.net/mof3497u/