How to find controls inside a class with specific class name

Hello all I have a table as follows

function checkAll2(rowClass, status) {
  var dynamicClass = $('.' + rowClass);
  // alert($('.1').find(":checkbox").length);
  alert($('input:checkbox.1').length);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<table id="table1">
  <tr>
    <td>1a:</td>
    <td><input type="checkbox" name="selected" value="1a" class="1"></td>
  </tr>
  <tr>
    <td>1b:
    </td>
    <td><input type="checkbox" name="selected" value="1b" class="1"></td>
  </tr>
</table>

Select All/None above<input type="checkbox" onclick="checkAll2(1,this.checked)" />

But what I need is I would like to reuse this for different classes too so I will pass rowClass so that my input:checkbox should be appended with rowClass and give me the count or the list of controls with that class