Session Storage to Show Table Column

I have a table where you can check a checkbox, and another column Quantity # and cell will appear. If it is unchecked, then the corresponding column/cell is hidden.

I can navigate throughout the page using a home button and search functions so if I come back to an originally checked row, then the Quantity # column is no longer visible even though the row is still checked.

I want to use session storage to be able to keep the Quantity # column and cells visible throughout the session until the page is closed, but only if the row is checked. I was able to use session storage to keep the checkboxes checked, but am having a problem with getting the Quantity # column to remain visible as long as the checkbox is checked for that row.

How can I do this?

JavaScript for the session storage for the checkbox:

$(function(){
    $(':checkbox').each(function() {
        // Iterate over the checkboxes and set their "check" values based on the session data
        var $el = $(this);
        $el.prop('checked', sessionStorage[$el.prop('id')] === 'true');
    });

    $('input:checkbox').on('change', function() {
        // save the individual checkbox in the session inside the `change` event, 
        // using the checkbox "id" attribute
        var $el = $(this);
        sessionStorage[$el.prop('id')] = $el.is(':checked');
    });
});

JavaScript for the appearing table column/cell:

$(function () {
    $(".check").change(function(){
    $(this).closest('tr').find('td.quantity_num').toggle(this.checked);
    console.log($('input.check').is(':checked'));
    var quantity = $(this).closest('tr').find('td.quantity').data('quantity');
        console.log(quantity);

  if($('input.check').is(':checked'))
    $(this).closest('table').find('th.num').toggle(true);
    else
    $(this).closest('table').find('th.num').toggle(false);



    $(this).closest("tr").find(".spinner" ).spinner({
      spin: function( event, ui ) {
        if ( ui.value > quantity ) {
          $( this ).spinner( "value", quantity );
          return false;
        } else if ( ui.value <= 1 ) {
          $( this ).spinner( "value", 1 );
          return false;
        }

        var test = ui.value;
        sessionStorage.setItem("test", JSON.stringify(test));
        var testtrue = sessionStorage.getItem("test");
        console.log(JSON.parse(testtrue));

      }
    });
  });
  });

HTML/PHP for table:

<table id="merchTable" cellspacing="5" class="sortable">
    <thead>
        <tr class="ui-widget-header">
            <th class="sorttable_nosort"></th>
            <th class="sorttable_nosort">Loc</th>
            <th class="merchRow">Report Code</th>
            <th class="merchRow">SKU</th>
            <th class="merchRow">Special ID</th>
            <th class="merchRow">Description</th>
            <th class="merchRow">Quantity</th>
            <th class="sorttable_nosort">Unit</th>
            <th style="display: none;" class="num">Quantity #</th>
        </tr>
    </thead>
    <tbody>

        <?php foreach ($dbh->query($query) as $row) {?>

        <tr>
            <td class="ui-widget-content"><input type="checkbox" class="check" name="check" id="checkid-<?php echo intval ($row['ID'])?>"></td>
            <td class="loc ui-widget-content"><input type="hidden"><?php echo $row['Loc'];?></td>
            <td name="rows[0][0][rp-code]" class="rp-code ui-widget-content" align="center" id="rp-code-<?php echo intval ($row['Rp-Code'])?>"><?php echo $row['Rp-Code'];?></td>
            <td name="rows[0][0][sku]" class="sku ui-widget-content" id="sku-<?php echo intval ($row['SKU'])?>"><?php echo $row['SKU'];?></td>
            <td name="rows[0][0][special-id]" class="special-id ui-widget-content" align="center" id="special-id-<?php echo intval ($row['Special-ID'])?>"><?php echo $row['Special-ID'];?></td>
            <td name="rows[0][0][description]" class="description ui-widget-content" id="description-<?php echo intval ($row['Description'])?>"><?php echo $row['Description'];?></td>
            <td name="rows[0][0][quantity]" class="quantity ui-widget-content" data-quantity="<?php echo $row['Quantity'] ?>" align="center" id="quantity-<?php echo intval ($row['Quantity'])?>"><?php echo $row['Quantity'];?></td>
            <td name="rows[0][0][unit]" class="unit ui-widget-content" id="unit-<?php echo intval ($row['Unit'])?>"><?php echo $row['Unit'];?></td>
            <td name="rows[0][0][quant]" style="display: none;" class="quantity_num ui-widget-content"><input type="textbox" style="width: 100px;" class="spinner" id="spin-<?php echo intval ($row['ID'])?>"></td>
        </tr>

    <?php } ?>

    </tbody>
</table>