sharepoint - Javascript - Need to Work With Elements With Generic Classes -

i have javascript written accommodate needs conditional formatting on sharepoint page. there few tables, in web parts, in making changes style of of cells. used nodelist accomplish needs (no unique ids), , working alright, until changes made table threw nodelist references off (i knew inevitable..). wondering if has input on how better select or distinguish between elements have same class name , contain data change.

example:

<td class="asd"> blah blah blah </td> <td class="asd"> content content </td> <td class="asd"> test test test </td> 

select them using getelementsbyclassname()

var tds = document.getelementsbyclassname('asd');  console.log(tds);  (var = 0; < tds.length; i++) {    tds[i].style.color = 'green';  }

<table>    <tr>      <td class="asd">blah blah blah</td>      <td class="asd">content content</td>      <td class="asd">test test test</td>    </tr>  </table>