JSFiddle - React, Tailwind, and code Playground
HTML
<select class="selector">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<br/>
Previous value:<div id="output"></div>
JavaScript
$(".selector").change(function() {
// Get the previous value (if any)
var prev = $(this).data("prev");
// Store the new value for next time
$(this).data("prev",$(this).val());
$('#output').html(prev);
});