JSFiddle - React, Tailwind, and code Playground
by Justin
HTML
<select class="component" name="blah">
<option value="1">1</option>
<option value="2">2</option>
</select>
<select class="component" name="blah2">
<option value="3">3</option>
<option value="4">4</option>
</select>
<select name="combined"></select>
JavaScript
$(function () {
$('.component').change(function () {
$('select[name="combined"]').append('<option value="' + $(this).val() + '">' + $(this).val() + '</option>')
})
})