jquery - Change colspan of cells with identical content, so they appear to be merged

Question

I have got a table with redundant data in cells. [Left table]

I need to join them into one cell. [Right table]

Structure of table:

<table>
  <tr>
    <td class="bold">Value1:</td>
    <td class="green">A</td>
    <td class="green">A</td>
    <td class="green">A</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">B</td>
    <td class="green">B</td>
  </tr>
  <tr>
    <td class="bold">Value2:</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">C</td>
    <td class="green">C</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">D</td>
    <td>&nbsp;</td>
  </tr>
</table>

I am able to hide redundant cell, but I need to set colspan somehow.

$(document).ready(function () {

var all = $('.green');
var seen = {};
all.each(function () {
    var txt = $(this).text();
    if (seen[txt]) {
        $(this).hide();
    }
    else {
        seen[txt] = true;
    }
});


});

Answer 1

$(document).ready(function() {

  var all = $('.green');
  var first;
  var prev = undefined;
  var colspan = 1;

  var setColspan = function() {
    first.attr('colspan', colspan);
    colspan = 1;
  }

  all.each(function() {
    var txt = $(this).text();
    if (prev === txt) {
      colspan += 1;
      $(this).remove();
    } else {
      // doesnt match, set colspan on first and reset colspan counter
      if (colspan > 1) {
        setColspan();
      }
      first = $(this);
      prev = txt;
    }
  });

  if (colspan > 1) {
    setColspan();
  }

});

td {
  border: 1px solid;
  text-align: center;
  min-width: 25px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.0.0/jquery.min.js"></script>
<table>
  <tr>
    <td class="bold">Value1:</td>
    <td class="green">A</td>
    <td class="green">A</td>
    <td class="green">A</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">B</td>
    <td class="green">B</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td> 
    <td>&nbsp;</td> 
  </tr>
  <tr>
    <td class="bold">Value2:</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">C</td>
    <td class="green">C</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="green">D</td>
    <td>&nbsp;</td>
  </tr>
</table>