How to add an active class to the current element with JavaScript?

JavascriptWeb DevelopmentObject Oriented Programming

To add an active class to the current element with JavaScript, the code is as follows −


 Live Demo

<!DOCTYPE html>
<meta name="viewport" content="width=device-width, initial-scale=1" />
   .btn {
      border: none;
      outline: none;
      padding: 10px 16px;
      background-color: #6ea2f0;
      cursor: pointer;
      font-size: 18px;
   .active, .btn:hover {
      background-color: #666;
      color: white;
<h1>Active Button Example</h1>
<div id="sampleDiv">
<button class="btn">Giraffe</button>
<button class="btn active">Cow</button>
<button class="btn">Lion</button>
<button class="btn">Leopard</button>
<button class="btn">Cheetah</button>
<h2>Press any of the above button to set it class to active</h2>
   var btns = document.querySelectorAll(".btn");
   Array.from(btns).forEach(item => {
      item.addEventListener("click", () => {
         var selected = document.getElementsByClassName("active");
         selected[0].className = selected[0].className.replace(" active", "");
         item.className += " active";


The above code will produce the following output −

On clicking any other button −

Published on 08-May-2020 17:05:22