JSFiddle - React, Tailwind, and code Playground

HTML

<select size="6" id="selecttest"><option value = "1">1</option><option value = "2" selected>2</option><option value = "3">3</option><option value = "4">4</option><option value = "5">5</option><option value = "6">6</option><option value = "7">7</option><option value = "8">8</option><option value = "9">9</option><option value = "10">10</option><option value = "11">11</option><option value = "12">12</option></select>

JavaScript

$(function () {
		$('#selecttest').change(function () {
			alert($(this).val());
		});
	});