What is the best way to add an event in JavaScript?

The best way to add an event to any element is to use the addEventListener() method.

Following is the code to add an event in JavaScript −


 Live Demo

<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
      font-size: 20px;
      font-weight: 500;
      color: rebeccapurple;
<h1>Adding event in JavaScript</h1>
<div style="color: green;" class="result"<Hello world>/div>
<button class="Btn">CLICK HERE</button>
Click on the above button to increment the font size of above text
   let resEle = document.querySelector(".result");
   document.querySelector(".Btn").addEventListener("click", () => {
      resEle.style.fontSize = "34px";


The above code will produce the following output −

On clicking the ‘CLICK HERE’ button −