<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
width: 100px;
height: 100px;
background: yellow;
-webkit-transition: 2s;
transition: 2s;
}
#myDIV:hover {
width: 400px;
}
</style>
</head>
<body>
<p>Hover over the div element below, and wait for the transition effect to end.</p>
<p>The propertyName property returns the name of the CSS property the transition effect is for.</p>
<div id="myDIV"></div>
<script>
document.getElementById("myDIV").addEventListener("webkitTransitionEnd", myFunction);
document.getElementById("myDIV").addEventListener("transitionend", myFunction);
function myFunction(event) {
this.innerHTML = "CSS Property used: " + event.propertyName;
}
</script>
</body>
</html>