How To Pass A Php Variable From A Dropdown To Another Dropdown Using Php?

).on("change", function(){ var selectedClass = $(this).val(); //store the selected value $('#select2').val(""); //clear the second dropdown selected value //now loop through the 2nd dropdown, hide the unwanted options $('#select2 option').each(function () { var newValue = $(this).attr('class'); if (selectedClass != newValue && selectedClass != "") { $(this).hide(); } else{$(this).show(); } }); }); });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<select id="select1">
  <option value=""></option>
  <option value="number1">number 1</option>
  <option value="number2">number 2</option>
</select>
<select id="select2">
  <option class=""></option>
  <option class="number1">number 1.1</option>
  <option class="number2">number 2.1</option>
  <option class="number1">number 1.2</option>
  <option class="number2">number 2.3</option>
  <option class="number1">number 1.3</option>
  <option class="number1">number 1.2</option>
</select>