JSFiddle - React, Tailwind, and code Playground

HTML

<input id="B1" type="button" value="XXX" />
<input id="B2" type="button" value="YYY" />

JavaScript

window.onload = function() {
          var btn = document.getElementById("B1");
          btn.addEventListener("click", F1);
        }
        $(function() {
          $("#B2").bind('click', F2);
        });

        function F1(event) {
          alert(event.target.value);
        }

        function F2(event) {
          alert($(event.target).val());
        }