The onmouseenter event triggers when you mouse hover the pointer.
Example
You can try to run the following code to learn how to work with onmouseenter event in JavaScript −
<html>
<head>
<script>
<!--
function sayHello() {
alert("Mouse Hover")
}
//-->
</script>
</head>
<body>
<p onmouseenter = "sayHello()">This is demo text for mouseenter event.</p>
</body>
</html>