Child Count in Table Tr - total number of td in row

/*
<table id="table00">
    <tr id="trOne">
      <td>Item A</td>
      <td>Item B</td>
      <td>Item C</td>
    </tr>
</table>
*/

doChildCount("trOne");

function doChildCount(strId){
    var thisChildCount = document.getElementById(strId).childElementCount;
    console.log(thisChildCount);
}