JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" id="demoInput" />
<select id="demoSelect" />
<option>Option 1</option>
<option>Option 2</option>
<option>Option 3</option>
</select>
JavaScript
$('#demoSelect').change(function(){
$('#demoInput').val(2);
});