What is an HTML event handler?

An HTML event handler is a JavaScript function that is executed in response to a specific event occurring on an HTML element. Events can include user interactions such as clicks, key presses, mouse movements, and more.

Event handlers can be defined directly in the HTML using attributes like onclick, onchange, or onkeyup, or they can be attached using JavaScript with methods like addEventListener.

For example, here’s how you can set up an event handler for a button click:

<button id="myButton">Click Here</button>
<div id="myDiv"></div>

<script>
 function handleButtonClick() {
   document.getElementById("myDiv").innerHTML = "Hello, World!";
 }

 document.getElementById("myButton").addEventListener("click", handleButtonClick);
</script>

In this example, when the button is clicked, the handleButtonClick function is called, updating the content of the div element.