JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="myFunction(this)">Button 1</button>
<button onclick="myFunction(this)">Button 2</button>

<div id="demo">Starting Text</div>

JavaScript

function myFunction(btn) {
  var demo = document.getElementById("demo");
  
  if (btn.innerHTML === "Button 1") {
    demo.innerHTML = "Swapped text!";
  } else {
    demo.innerHTML = "Im not button 1";
  }
}