How to add rowspan in table column if values is the same using jQuery

By using jQUery

<table border=1 id="myTable">
        <tr>
            <td>A</td>
            <td>1</td>
        </tr>
        <tr>
            <td>A</td>
            <td>2</td>
        </tr>
        <tr>
            <td>b</td>
            <td>1</td>
        </tr>
        <tr>
            <td>c</td>
            <td>1</td>
        </tr>
        <tr>
            <td>c</td>
            <td>1</td>
        </tr>
    </table>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>

<script>
    $(document).ready(function() {
       var span = 1;
       var prevTD = "";
       var prevTDVal = "";
       $("#myTable tr td:first-child").each(function() { //for each first td in every tr
          var $this = $(this);
          if ($this.text() == prevTDVal) { // check value of previous td text
             span++;
             if (prevTD != "") {
                prevTD.attr("rowspan", span); // add attribute to previous td
                $this.remove(); // remove current td
             }
          } else {
             prevTD     = $this; // store current td 
             prevTDVal  = $this.text();
             span       = 1;
          }
       });
    });
</script>